First Local Commit - After Clean up.

Signed-off-by: Rick Hays <rhays@haysgang.com>

system/Database/BasePreparedQuery.php

@@ -0,0 +1,274 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+use CodeIgniter\Database\MySQLi\Connection;
+use CodeIgniter\Events\Events;
+
+/**
+ * Base prepared query
+ */
+abstract class BasePreparedQuery implements PreparedQueryInterface
+{
+
+	/**
+	 * The prepared statement itself.
+	 *
+	 * @var resource|\mysqli_stmt
+	 */
+	protected $statement;
+
+	/**
+	 * The error code, if any.
+	 *
+	 * @var integer
+	 */
+	protected $errorCode;
+
+	/**
+	 * The error message, if any.
+	 *
+	 * @var string
+	 */
+	protected $errorString;
+
+	/**
+	 * Holds the prepared query object
+	 * that is cloned during execute.
+	 *
+	 * @var Query
+	 */
+	protected $query;
+
+	/**
+	 * A reference to the db connection to use.
+	 *
+	 * @var BaseConnection|MySQLi\Connection
+	 */
+	protected $db;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor.
+	 *
+	 * @param \CodeIgniter\Database\ConnectionInterface $db
+	 */
+	public function __construct(ConnectionInterface $db)
+	{
+		$this->db = &$db;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares the query against the database, and saves the connection
+	 * info necessary to execute the query later.
+	 *
+	 * NOTE: This version is based on SQL code. Child classes should
+	 * override this method.
+	 *
+	 * @param string $sql
+	 * @param array  $options    Passed to the connection's prepare statement.
+	 * @param string $queryClass
+	 *
+	 * @return mixed
+	 */
+	public function prepare(string $sql, array $options = [], string $queryClass = 'CodeIgniter\\Database\\Query')
+	{
+		// We only supports positional placeholders (?)
+		// in order to work with the execute method below, so we
+		// need to replace our named placeholders (:name)
+		$sql = preg_replace('/:[^\s,)]+/', '?', $sql);
+
+		/**
+		 * @var \CodeIgniter\Database\Query $query
+		 */
+		$query = new $queryClass($this->db);
+
+		$query->setQuery($sql);
+
+		if (! empty($this->db->swapPre) && ! empty($this->db->DBPrefix))
+		{
+			$query->swapPrefix($this->db->DBPrefix, $this->db->swapPre);
+		}
+
+		$this->query = $query;
+
+		return $this->_prepare($query->getOriginalQuery(), $options);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * The database-dependent portion of the prepare statement.
+	 *
+	 * @param string $sql
+	 * @param array  $options Passed to the connection's prepare statement.
+	 *
+	 * @return mixed
+	 */
+	abstract public function _prepare(string $sql, array $options = []);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Takes a new set of data and runs it against the currently
+	 * prepared query. Upon success, will return a Results object.
+	 *
+	 * @param array $data
+	 *
+	 * @return ResultInterface
+	 */
+	public function execute(...$data)
+	{
+		// Execute the Query.
+		$startTime = microtime(true);
+
+		$result = $this->_execute($data);
+
+		// Update our query object
+		$query = clone $this->query;
+		$query->setBinds($data);
+
+		$query->setDuration($startTime);
+
+		// Let others do something with this query
+		Events::trigger('DBQuery', $query);
+
+		// Return a result object
+		$resultClass = str_replace('PreparedQuery', 'Result', get_class($this));
+
+		$resultID = $this->_getResult();
+
+		return new $resultClass($this->db->connID, $resultID);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * The database dependant version of the execute method.
+	 *
+	 * @param array $data
+	 *
+	 * @return boolean
+	 */
+	abstract public function _execute(array $data): bool;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result object for the prepared query.
+	 *
+	 * @return mixed
+	 */
+	abstract public function _getResult();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Explicitly closes the statement.
+	 *
+	 * @return null|void
+	 */
+	public function close()
+	{
+		if (! is_object($this->statement))
+		{
+			return;
+		}
+
+		$this->statement->close();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the SQL that has been prepared.
+	 *
+	 * @return string
+	 */
+	public function getQueryString(): string
+	{
+		if (! $this->query instanceof QueryInterface)
+		{
+			throw new \BadMethodCallException('Cannot call getQueryString on a prepared query until after the query has been prepared.');
+		}
+
+		return $this->query->getQuery();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * A helper to determine if any error exists.
+	 *
+	 * @return boolean
+	 */
+	public function hasError(): bool
+	{
+		return ! empty($this->errorString);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error code created while executing this statement.
+	 *
+	 * @return integer
+	 */
+	public function getErrorCode(): int
+	{
+		return $this->errorCode;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error message created while executing this statement.
+	 *
+	 * @return string
+	 */
+	public function getErrorMessage(): string
+	{
+		return $this->errorString;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/BaseResult.php

@@ -0,0 +1,629 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Class BaseResult
+ */
+abstract class BaseResult implements ResultInterface
+{
+
+	/**
+	 * Connection ID
+	 *
+	 * @var resource|object
+	 */
+	public $connID;
+
+	/**
+	 * Result ID
+	 *
+	 * @var resource|object
+	 */
+	public $resultID;
+
+	/**
+	 * Result Array
+	 *
+	 * @var array[]
+	 */
+	public $resultArray = [];
+
+	/**
+	 * Result Object
+	 *
+	 * @var object[]
+	 */
+	public $resultObject = [];
+
+	/**
+	 * Custom Result Object
+	 *
+	 * @var object[]
+	 */
+	public $customResultObject = [];
+
+	/**
+	 * Current Row index
+	 *
+	 * @var integer
+	 */
+	public $currentRow = 0;
+
+	/**
+	 * Number of rows
+	 *
+	 * @var integer
+	 */
+	public $numRows;
+
+	/**
+	 * Row data
+	 *
+	 * @var array
+	 */
+	public $rowData;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor
+	 *
+	 * @param object|resource $connID
+	 * @param object|resource $resultID
+	 */
+	public function __construct(&$connID, &$resultID)
+	{
+		$this->connID   = $connID;
+		$this->resultID = $resultID;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Retrieve the results of the query. Typically an array of
+	 * individual data rows, which can be either an 'array', an
+	 * 'object', or a custom class name.
+	 *
+	 * @param string $type The row type. Either 'array', 'object', or a class name to use
+	 *
+	 * @return array
+	 */
+	public function getResult(string $type = 'object'): array
+	{
+		if ($type === 'array')
+		{
+			return $this->getResultArray();
+		}
+		elseif ($type === 'object')
+		{
+			return $this->getResultObject();
+		}
+
+		return $this->getCustomResultObject($type);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of custom objects.
+	 *
+	 * @param string $className The name of the class to use.
+	 *
+	 * @return mixed
+	 */
+	public function getCustomResultObject(string $className)
+	{
+		if (isset($this->customResultObject[$className]))
+		{
+			return $this->customResultObject[$className];
+		}
+
+		if (is_bool($this->resultID) || ! $this->resultID || $this->numRows === 0)
+		{
+			return [];
+		}
+
+		// Don't fetch the result set again if we already have it
+		$_data = null;
+		if (($c = count($this->resultArray)) > 0)
+		{
+			$_data = 'result_array';
+		}
+		elseif (($c = count($this->resultObject)) > 0)
+		{
+			$_data = 'result_object';
+		}
+
+		if ($_data !== null)
+		{
+			for ($i = 0; $i < $c; $i ++)
+			{
+				$this->customResultObject[$className][$i] = new $className();
+
+				foreach ($this->{$_data}[$i] as $key => $value)
+				{
+					$this->customResultObject[$className][$i]->$key = $value;
+				}
+			}
+
+			return $this->customResultObject[$className];
+		}
+
+		is_null($this->rowData) || $this->dataSeek(0);
+		$this->customResultObject[$className] = [];
+
+		while ($row = $this->fetchObject($className))
+		{
+			if (method_exists($row, 'syncOriginal'))
+			{
+				$row->syncOriginal();
+			}
+
+			$this->customResultObject[$className][] = $row;
+		}
+
+		return $this->customResultObject[$className];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of arrays.
+	 *
+	 * If no results, an empty array is returned.
+	 *
+	 * @return array
+	 */
+	public function getResultArray(): array
+	{
+		if (! empty($this->resultArray))
+		{
+			return $this->resultArray;
+		}
+
+		// In the event that query caching is on, the result_id variable
+		// will not be a valid resource so we'll simply return an empty
+		// array.
+		if (is_bool($this->resultID) || ! $this->resultID || $this->numRows === 0)
+		{
+			return [];
+		}
+
+		if ($this->resultObject)
+		{
+			foreach ($this->resultObject as $row)
+			{
+				$this->resultArray[] = (array) $row;
+			}
+
+			return $this->resultArray;
+		}
+
+		is_null($this->rowData) || $this->dataSeek(0);
+		while ($row = $this->fetchAssoc())
+		{
+			$this->resultArray[] = $row;
+		}
+
+		return $this->resultArray;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of objects.
+	 *
+	 * If no results, an empty array is returned.
+	 *
+	 * @return array
+	 */
+	public function getResultObject(): array
+	{
+		if (! empty($this->resultObject))
+		{
+			return $this->resultObject;
+		}
+
+		// In the event that query caching is on, the result_id variable
+		// will not be a valid resource so we'll simply return an empty
+		// array.
+		if (is_bool($this->resultID) || ! $this->resultID || $this->numRows === 0)
+		{
+			return [];
+		}
+
+		if ($this->resultArray)
+		{
+			foreach ($this->resultArray as $row)
+			{
+				$this->resultObject[] = (object) $row;
+			}
+
+			return $this->resultObject;
+		}
+
+		is_null($this->rowData) || $this->dataSeek(0);
+		while ($row = $this->fetchObject())
+		{
+			if (method_exists($row, 'syncOriginal'))
+			{
+				$row->syncOriginal();
+			}
+
+			$this->resultObject[] = $row;
+		}
+
+		return $this->resultObject;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Wrapper object to return a row as either an array, an object, or
+	 * a custom class.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param mixed  $n    The index of the results to return
+	 * @param string $type The type of result object. 'array', 'object' or class name.
+	 *
+	 * @return mixed
+	 */
+	public function getRow($n = 0, string $type = 'object')
+	{
+		if (! is_numeric($n))
+		{
+			// We cache the row data for subsequent uses
+			is_array($this->rowData) || $this->rowData = $this->getRowArray(0);
+
+			// array_key_exists() instead of isset() to allow for NULL values
+			if (empty($this->rowData) || ! array_key_exists($n, $this->rowData))
+			{
+				return null;
+			}
+
+			return $this->rowData[$n];
+		}
+
+		if ($type === 'object')
+		{
+			return $this->getRowObject($n);
+		}
+		elseif ($type === 'array')
+		{
+			return $this->getRowArray($n);
+		}
+
+		return $this->getCustomRowObject($n, $type);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a row as a custom class instance.
+	 *
+	 * If row doesn't exists, returns null.
+	 *
+	 * @param integer $n
+	 * @param string  $className
+	 *
+	 * @return mixed
+	 */
+	public function getCustomRowObject(int $n, string $className)
+	{
+		isset($this->customResultObject[$className]) || $this->getCustomResultObject($className);
+
+		if (empty($this->customResultObject[$className]))
+		{
+			return null;
+		}
+
+		if ($n !== $this->currentRow && isset($this->customResultObject[$className][$n]))
+		{
+			$this->currentRow = $n;
+		}
+
+		return $this->customResultObject[$className][$this->currentRow];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a single row from the results as an array.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function getRowArray(int $n = 0)
+	{
+		$result = $this->getResultArray();
+		if (empty($result))
+		{
+			return null;
+		}
+
+		if ($n !== $this->currentRow && isset($result[$n]))
+		{
+			$this->currentRow = $n;
+		}
+
+		return $result[$this->currentRow];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a single row from the results as an object.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function getRowObject(int $n = 0)
+	{
+		$result = $this->getResultObject();
+		if (empty($result))
+		{
+			return null;
+		}
+
+		if ($n !== $this->customResultObject && isset($result[$n]))
+		{
+			$this->currentRow = $n;
+		}
+
+		return $result[$this->currentRow];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Assigns an item into a particular column slot.
+	 *
+	 * @param mixed $key
+	 * @param mixed $value
+	 *
+	 * @return mixed
+	 */
+	public function setRow($key, $value = null)
+	{
+		// We cache the row data for subsequent uses
+		if (! is_array($this->rowData))
+		{
+			$this->rowData = $this->getRowArray(0);
+		}
+
+		if (is_array($key))
+		{
+			foreach ($key as $k => $v)
+			{
+				$this->rowData[$k] = $v;
+			}
+
+			return;
+		}
+
+		if ($key !== '' && $value !== null)
+		{
+			$this->rowData[$key] = $value;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "first" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getFirstRow(string $type = 'object')
+	{
+		$result = $this->getResult($type);
+
+		return (empty($result)) ? null : $result[0];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "last" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getLastRow(string $type = 'object')
+	{
+		$result = $this->getResult($type);
+
+		return (empty($result)) ? null : $result[count($result) - 1];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "next" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getNextRow(string $type = 'object')
+	{
+		$result = $this->getResult($type);
+		if (empty($result))
+		{
+			return null;
+		}
+
+		return isset($result[$this->currentRow + 1]) ? $result[++ $this->currentRow] : null;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "previous" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getPreviousRow(string $type = 'object')
+	{
+		$result = $this->getResult($type);
+		if (empty($result))
+		{
+			return null;
+		}
+
+		if (isset($result[$this->currentRow - 1]))
+		{
+			-- $this->currentRow;
+		}
+
+		return $result[$this->currentRow];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an unbuffered row and move the pointer to the next row.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getUnbufferedRow(string $type = 'object')
+	{
+		if ($type === 'array')
+		{
+			return $this->fetchAssoc();
+		}
+		elseif ($type === 'object')
+		{
+			return $this->fetchObject();
+		}
+
+		return $this->fetchObject($type);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Gets the number of fields in the result set.
+	 *
+	 * @return integer
+	 */
+	abstract public function getFieldCount(): int;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of column names in the result set.
+	 *
+	 * @return array
+	 */
+	abstract public function getFieldNames(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of objects representing field meta-data.
+	 *
+	 * @return array
+	 */
+	abstract public function getFieldData(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Frees the current result.
+	 *
+	 * @return void
+	 */
+	abstract public function freeResult();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Moves the internal pointer to the desired offset. This is called
+	 * internally before fetching results to make sure the result set
+	 * starts at zero.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	abstract public function dataSeek(int $n = 0);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an array.
+	 *
+	 * Overridden by driver classes.
+	 *
+	 * @return mixed
+	 */
+	abstract protected function fetchAssoc();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an object.
+	 *
+	 * Overridden by child classes.
+	 *
+	 * @param string $className
+	 *
+	 * @return object
+	 */
+	abstract protected function fetchObject(string $className = 'stdClass');
+
+	//--------------------------------------------------------------------
+}

system/Database/BaseUtils.php

@@ -0,0 +1,458 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Class BaseUtils
+ */
+abstract class BaseUtils
+{
+
+	/**
+	 * Database object
+	 *
+	 * @var object
+	 */
+	protected $db;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * List databases statement
+	 *
+	 * @var string
+	 */
+	protected $listDatabases = false;
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var string
+	 */
+	protected $optimizeTable = false;
+
+	/**
+	 * REPAIR TABLE statement
+	 *
+	 * @var string
+	 */
+	protected $repairTable = false;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param ConnectionInterface|object $db
+	 */
+	public function __construct(ConnectionInterface &$db)
+	{
+		$this->db = & $db;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * List databases
+	 *
+	 * @return array|boolean
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function listDatabases()
+	{
+		// Is there a cached result?
+		if (isset($this->db->dataCache['db_names']))
+		{
+			return $this->db->dataCache['db_names'];
+		}
+		elseif ($this->listDatabases === false)
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unsupported feature of the database platform you are using.');
+			}
+			return false;
+		}
+
+		$this->db->dataCache['db_names'] = [];
+
+		$query = $this->db->query($this->listDatabases);
+		if ($query === false)
+		{
+			return $this->db->dataCache['db_names'];
+		}
+
+		for ($i = 0, $query = $query->getResultArray(), $c = count($query); $i < $c; $i ++)
+		{
+			$this->db->dataCache['db_names'][] = current($query[$i]);
+		}
+
+		return $this->db->dataCache['db_names'];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Determine if a particular database exists
+	 *
+	 * @param  string $database_name
+	 * @return boolean
+	 */
+	public function databaseExists(string $database_name): bool
+	{
+		return in_array($database_name, $this->listDatabases());
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Optimize Table
+	 *
+	 * @param  string $table_name
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function optimizeTable(string $table_name)
+	{
+		if ($this->optimizeTable === false)
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unsupported feature of the database platform you are using.');
+			}
+			return false;
+		}
+
+		$query = $this->db->query(sprintf($this->optimizeTable, $this->db->escapeIdentifiers($table_name)));
+		if ($query !== false)
+		{
+			$query = $query->getResultArray();
+			return current($query);
+		}
+
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Optimize Database
+	 *
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function optimizeDatabase()
+	{
+		if ($this->optimizeTable === false)
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unsupported feature of the database platform you are using.');
+			}
+			return false;
+		}
+
+		$result = [];
+		foreach ($this->db->listTables() as $table_name)
+		{
+			$res = $this->db->query(sprintf($this->optimizeTable, $this->db->escapeIdentifiers($table_name)));
+			if (is_bool($res))
+			{
+				return $res;
+			}
+
+			// Build the result array...
+
+			$res = $res->getResultArray();
+
+			// Postgre & SQLite3 returns empty array
+			if (empty($res))
+			{
+				$key = $table_name;
+			}
+			else
+			{
+				$res  = current($res);
+				$key  = str_replace($this->db->database . '.', '', current($res));
+				$keys = array_keys($res);
+				unset($res[$keys[0]]);
+			}
+
+			$result[$key] = $res;
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Repair Table
+	 *
+	 * @param  string $table_name
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function repairTable(string $table_name)
+	{
+		if ($this->repairTable === false)
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unsupported feature of the database platform you are using.');
+			}
+			return false;
+		}
+
+		$query = $this->db->query(sprintf($this->repairTable, $this->db->escapeIdentifiers($table_name)));
+		if (is_bool($query))
+		{
+			return $query;
+		}
+
+		$query = $query->getResultArray();
+		return current($query);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generate CSV from a query result object
+	 *
+	 * @param ResultInterface $query     Query result object
+	 * @param string          $delim     Delimiter (default: ,)
+	 * @param string          $newline   Newline character (default: \n)
+	 * @param string          $enclosure Enclosure (default: ")
+	 *
+	 * @return string
+	 */
+	public function getCSVFromResult(ResultInterface $query, string $delim = ',', string $newline = "\n", string $enclosure = '"')
+	{
+		$out = '';
+		// First generate the headings from the table column names
+		foreach ($query->getFieldNames() as $name)
+		{
+			$out .= $enclosure . str_replace($enclosure, $enclosure . $enclosure, $name) . $enclosure . $delim;
+		}
+
+		$out = substr($out, 0, -strlen($delim)) . $newline;
+
+		// Next blast through the result array and build out the rows
+		while ($row = $query->getUnbufferedRow('array'))
+		{
+			$line = [];
+			foreach ($row as $item)
+			{
+				$line[] = $enclosure . str_replace($enclosure, $enclosure . $enclosure, $item) . $enclosure;
+			}
+			$out .= implode($delim, $line) . $newline;
+		}
+
+		return $out;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generate XML data from a query result object
+	 *
+	 * @param ResultInterface $query  Query result object
+	 * @param array           $params Any preferences
+	 *
+	 * @return string
+	 */
+	public function getXMLFromResult(ResultInterface $query, array $params = []): string
+	{
+		// Set our default values
+		foreach (['root' => 'root', 'element' => 'element', 'newline' => "\n", 'tab' => "\t"] as $key => $val)
+		{
+			if (! isset($params[$key]))
+			{
+				$params[$key] = $val;
+			}
+		}
+
+		// Create variables for convenience
+		extract($params);
+
+		// Load the xml helper
+		helper('xml');
+		// Generate the result
+		$xml = '<' . $root . '>' . $newline;
+		while ($row = $query->getUnbufferedRow())
+		{
+			$xml .= $tab . '<' . $element . '>' . $newline;
+			foreach ($row as $key => $val)
+			{
+				$val  = (! empty($val)) ? xml_convert($val) : '';
+				$xml .= $tab . $tab . '<' . $key . '>' . $val . '</' . $key . '>' . $newline;
+			}
+			$xml .= $tab . '</' . $element . '>' . $newline;
+		}
+
+		return $xml . '</' . $root . '>' . $newline;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Database Backup
+	 *
+	 * @param  array|string $params
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function backup($params = [])
+	{
+		// If the parameters have not been submitted as an
+		// array then we know that it is simply the table
+		// name, which is a valid short cut.
+		if (is_string($params))
+		{
+			$params = ['tables' => $params];
+		}
+
+		// Set up our default preferences
+		$prefs = [
+			'tables'             => [],
+			'ignore'             => [],
+			'filename'           => '',
+			'format'             => 'gzip', // gzip, zip, txt
+			'add_drop'           => true,
+			'add_insert'         => true,
+			'newline'            => "\n",
+			'foreign_key_checks' => true,
+		];
+
+		// Did the user submit any preferences? If so set them....
+		if (! empty($params))
+		{
+			foreach ($prefs as $key => $val)
+			{
+				if (isset($params[$key]))
+				{
+					$prefs[$key] = $params[$key];
+				}
+			}
+		}
+
+		// Are we backing up a complete database or individual tables?
+		// If no table names were submitted we'll fetch the entire table list
+		if (empty($prefs['tables']))
+		{
+			$prefs['tables'] = $this->db->listTables();
+		}
+
+		// Validate the format
+		if (! in_array($prefs['format'], ['gzip', 'zip', 'txt'], true))
+		{
+			$prefs['format'] = 'txt';
+		}
+
+		// Is the encoder supported? If not, we'll either issue an
+		// error or use plain text depending on the debug settings
+		if (($prefs['format'] === 'gzip' && ! function_exists('gzencode'))
+			|| ( $prefs['format'] === 'zip' && ! function_exists('gzcompress')))
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('The file compression format you chose is not supported by your server.');
+			}
+
+			$prefs['format'] = 'txt';
+		}
+
+		// Was a Zip file requested?
+		if ($prefs['format'] === 'zip')
+		{
+			// Set the filename if not provided (only needed with Zip files)
+			if ($prefs['filename'] === '')
+			{
+				$prefs['filename'] = (count($prefs['tables']) === 1 ? $prefs['tables'] : $this->db->database)
+					. date('Y-m-d_H-i', time()) . '.sql';
+			}
+			else
+			{
+				// If they included the .zip file extension we'll remove it
+				if (preg_match('|.+?\.zip$|', $prefs['filename']))
+				{
+					$prefs['filename'] = str_replace('.zip', '', $prefs['filename']);
+				}
+
+				// Tack on the ".sql" file extension if needed
+				if (! preg_match('|.+?\.sql$|', $prefs['filename']))
+				{
+					$prefs['filename'] .= '.sql';
+				}
+			}
+
+			// Load the Zip class and output it
+			//          $CI =& get_instance();
+			//          $CI->load->library('zip');
+			//          $CI->zip->add_data($prefs['filename'], $this->_backup($prefs));
+			//          return $CI->zip->get_zip();
+		}
+		elseif ($prefs['format'] === 'txt') // Was a text file requested?
+		{
+			return $this->_backup($prefs);
+		}
+		elseif ($prefs['format'] === 'gzip') // Was a Gzip file requested?
+		{
+			return gzencode($this->_backup($prefs));
+		}
+
+		return;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform dependent version of the backup function.
+	 *
+	 * @param array|null $prefs
+	 *
+	 * @return mixed
+	 */
+	abstract public function _backup(array $prefs = null);
+
+	//--------------------------------------------------------------------
+}

system/Database/Config.php

@@ -0,0 +1,199 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+use CodeIgniter\Config\BaseConfig;
+
+/**
+ * Class Config
+ */
+class Config extends BaseConfig
+{
+
+	/**
+	 * Cache for instance of any connections that
+	 * have been requested as a "shared" instance.
+	 *
+	 * @var array
+	 */
+	static protected $instances = [];
+
+	/**
+	 * The main instance used to manage all of
+	 * our open database connections.
+	 *
+	 * @var \CodeIgniter\Database\Database
+	 */
+	static protected $factory;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Creates the default
+	 *
+	 * @param string|array $group     The name of the connection group to use,
+	 *                                or an array of configuration settings.
+	 * @param boolean      $getShared Whether to return a shared instance of the connection.
+	 *
+	 * @return BaseConnection
+	 */
+	public static function connect($group = null, bool $getShared = true)
+	{
+		// If a DB connection is passed in, just pass it back
+		if ($group instanceof BaseConnection)
+		{
+			return $group;
+		}
+
+		if (is_array($group))
+		{
+			$config = $group;
+			$group  = 'custom-' . md5(json_encode($config));
+		}
+
+		$config = $config ?? config('Database');
+
+		if (empty($group))
+		{
+			$group = ENVIRONMENT === 'testing' ? 'tests' : $config->defaultGroup;
+		}
+
+		if (is_string($group) && ! isset($config->$group) && strpos($group, 'custom-') !== 0)
+		{
+			throw new \InvalidArgumentException($group . ' is not a valid database connection group.');
+		}
+
+		if ($getShared && isset(static::$instances[$group]))
+		{
+			return static::$instances[$group];
+		}
+
+		static::ensureFactory();
+
+		if (isset($config->$group))
+		{
+			$config = $config->$group;
+		}
+
+		$connection = static::$factory->load($config, $group);
+
+		static::$instances[$group] = & $connection;
+
+		return $connection;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of all db connections currently made.
+	 *
+	 * @return array
+	 */
+	public static function getConnections(): array
+	{
+		return static::$instances;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Loads and returns an instance of the Forge for the specified
+	 * database group, and loads the group if it hasn't been loaded yet.
+	 *
+	 * @param string|array|null $group
+	 *
+	 * @return Forge
+	 */
+	public static function forge($group = null)
+	{
+		$db = static::connect($group);
+
+		return static::$factory->loadForge($db);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a new instance of the Database Utilities class.
+	 *
+	 * @param string|array|null $group
+	 *
+	 * @return BaseUtils
+	 */
+	public static function utils($group = null)
+	{
+		$db = static::connect($group);
+
+		return static::$factory->loadUtils($db);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a new instance of the Database Seeder.
+	 *
+	 * @param string|null $group
+	 *
+	 * @return Seeder
+	 */
+	public static function seeder(string $group = null)
+	{
+		$config = config('Database');
+
+		return new Seeder($config, static::connect($group));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Ensures the database Connection Manager/Factory is loaded and ready to use.
+	 */
+	protected static function ensureFactory()
+	{
+		if (static::$factory instanceof Database)
+		{
+			return;
+		}
+
+		static::$factory = new Database();
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/ConnectionInterface.php

@@ -0,0 +1,225 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Interface ConnectionInterface
+ *
+ * @package CodeIgniter\Database
+ */
+interface ConnectionInterface
+{
+
+	/**
+	 * Initializes the database connection/settings.
+	 *
+	 * @return mixed
+	 */
+	public function initialize();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Connect to the database.
+	 *
+	 * @param  boolean $persistent
+	 * @return mixed
+	 */
+	public function connect(bool $persistent = false);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Create a persistent database connection.
+	 *
+	 * @return mixed
+	 */
+	public function persistentConnect();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Keep or establish the connection if no queries have been sent for
+	 * a length of time exceeding the server's idle timeout.
+	 *
+	 * @return mixed
+	 */
+	public function reconnect();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the actual connection object. If both a 'read' and 'write'
+	 * connection has been specified, you can pass either term in to
+	 * get that connection. If you pass either alias in and only a single
+	 * connection is present, it must return the sole connection.
+	 *
+	 * @param string|null $alias
+	 *
+	 * @return mixed
+	 */
+	public function getConnection(string $alias = null);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Select a specific database table to use.
+	 *
+	 * @param string $databaseName
+	 *
+	 * @return mixed
+	 */
+	public function setDatabase(string $databaseName);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the name of the current database being used.
+	 *
+	 * @return string
+	 */
+	public function getDatabase(): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the last error encountered by this connection.
+	 *
+	 * @return mixed
+	 */
+	public function getError();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * The name of the platform in use (MySQLi, mssql, etc)
+	 *
+	 * @return string
+	 */
+	public function getPlatform(): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a string containing the version of the database being used.
+	 *
+	 * @return string
+	 */
+	public function getVersion(): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Orchestrates a query against the database. Queries must use
+	 * Database\Statement objects to store the query and build it.
+	 * This method works with the cache.
+	 *
+	 * Should automatically handle different connections for read/write
+	 * queries if needed.
+	 *
+	 * @param string $sql
+	 * @param mixed  ...$binds
+	 *
+	 * @return mixed
+	 */
+	public function query(string $sql, $binds = null);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Performs a basic query against the database. No binding or caching
+	 * is performed, nor are transactions handled. Simply takes a raw
+	 * query string and returns the database-specific result id.
+	 *
+	 * @param string $sql
+	 *
+	 * @return mixed
+	 */
+	public function simpleQuery(string $sql);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an instance of the query builder for this connection.
+	 *
+	 * @param string|array $tableName Table name.
+	 *
+	 * @return BaseBuilder Builder.
+	 */
+	public function table($tableName);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the last query's statement object.
+	 *
+	 * @return mixed
+	 */
+	public function getLastQuery();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * "Smart" Escaping
+	 *
+	 * Escapes data based on type.
+	 * Sets boolean and null types.
+	 *
+	 * @param mixed $str
+	 *
+	 * @return mixed
+	 */
+	public function escape($str);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Allows for custom calls to the database engine that are not
+	 * supported through our database layer.
+	 *
+	 * @param string $functionName
+	 * @param array  ...$params
+	 *
+	 * @return mixed
+	 */
+	public function callFunction(string $functionName, ...$params);
+
+	//--------------------------------------------------------------------
+}

system/Database/Database.php

@@ -0,0 +1,142 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Database Connection Factory
+ *
+ * Creates and returns an instance of the appropriate DatabaseConnection
+ *
+ * @package CodeIgniter\Database
+ */
+class Database
+{
+
+	/**
+	 * Maintains an array of the instances of all connections
+	 * that have been created. Helps to keep track of all open
+	 * connections for performance monitoring, logging, etc.
+	 *
+	 * @var array
+	 */
+	protected $connections = [];
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Parses the connection binds and returns an instance of
+	 * the driver ready to go.
+	 *
+	 * @param array  $params
+	 * @param string $alias
+	 *
+	 * @return   mixed
+	 * @internal param bool $useBuilder
+	 */
+	public function load(array $params = [], string $alias)
+	{
+		// No DB specified? Beat them senseless...
+		if (empty($params['DBDriver']))
+		{
+			throw new \InvalidArgumentException('You have not selected a database type to connect to.');
+		}
+
+		$className = strpos($params['DBDriver'], '\\') === false
+			? '\CodeIgniter\Database\\' . $params['DBDriver'] . '\\Connection'
+			: $params['DBDriver'] . '\\Connection';
+
+		$class = new $className($params);
+
+		// Store the connection
+		$this->connections[$alias] = $class;
+
+		return $this->connections[$alias];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Creates a new Forge instance for the current database type.
+	 *
+	 * @param ConnectionInterface|BaseConnection $db
+	 *
+	 * @return mixed
+	 */
+	public function loadForge(ConnectionInterface $db)
+	{
+		$className = strpos($db->DBDriver, '\\') === false ? '\CodeIgniter\Database\\' . $db->DBDriver . '\\Forge' : $db->DBDriver . '\\Forge';
+
+		// Make sure a connection exists
+		if (! $db->connID)
+		{
+			$db->initialize();
+		}
+
+		$class = new $className($db);
+
+		return $class;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Loads the Database Utilities class.
+	 *
+	 * @param ConnectionInterface|BaseConnection $db
+	 *
+	 * @return mixed
+	 */
+	public function loadUtils(ConnectionInterface $db)
+	{
+		$className = strpos($db->DBDriver, '\\') === false ? '\CodeIgniter\Database\\' . $db->DBDriver . '\\Utils' : $db->DBDriver . '\\Utils';
+
+		// Make sure a connection exists
+		if (! $db->connID)
+		{
+			$db->initialize();
+		}
+
+		$class = new $className($db);
+
+		return $class;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Exceptions/DataException.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace CodeIgniter\Database\Exceptions;
+
+class DataException extends \RuntimeException implements ExceptionInterface
+{
+	/**
+	 * Used by the Model's trigger() method when the callback cannot be found.
+	 *
+	 * @param string $method
+	 *
+	 * @return \CodeIgniter\Database\Exceptions\DataException
+	 */
+	public static function forInvalidMethodTriggered(string $method)
+	{
+		return new static(lang('Database.invalidEvent', [$method]));
+	}
+
+	/**
+	 * Used by Model's insert/update methods when there isn't
+	 * any data to actually work with.
+	 *
+	 * @param string $mode
+	 *
+	 * @return \CodeIgniter\Database\Exceptions\DataException
+	 */
+	public static function forEmptyDataset(string $mode)
+	{
+		return new static(lang('Database.emptyDataset', [$mode]));
+	}
+
+	/**
+	 * Thrown when an argument for one of the Model's methods
+	 * were empty or otherwise invalid, and they could not be
+	 * to work correctly for that method.
+	 *
+	 * @param string $argument
+	 *
+	 * @return \CodeIgniter\Database\Exceptions\DataException
+	 */
+	public static function forInvalidArgument(string $argument)
+	{
+		return new static(lang('Database.invalidArgument', [$argument]));
+	}
+
+	public static function forInvalidAllowedFields(string $model)
+	{
+		return new static(lang('Database.invalidAllowedFields', [$model]));
+	}
+
+	public static function forTableNotFound(string $table)
+	{
+		return new static(lang('Database.tableNotFound', [$table]));
+	}
+
+	public static function forEmptyInputGiven(string $argument)
+	{
+		return new static(lang('Database.forEmptyInputGiven', [$argument]));
+	}
+
+	public static function forFindColumnHaveMultipleColumns()
+	{
+		return new static(lang('Database.forFindColumnHaveMultipleColumns'));
+	}
+}

system/Database/Exceptions/DatabaseException.php

@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Exceptions;
+
+use CodeIgniter\Exceptions\ExceptionInterface;
+
+class DatabaseException extends \Error implements ExceptionInterface
+{
+	/**
+	 * Exit status code
+	 *
+	 * @var integer
+	 */
+	protected $code = 8;
+}

system/Database/Exceptions/ExceptionInterface.php

@@ -0,0 +1,13 @@
+<?php namespace CodeIgniter\Database\Exceptions;
+
+/**
+ * Provides a domain-level interface for broad capture
+ * of all database-related exceptions.
+ *
+ * catch (\CodeIgniter\Database\Exceptions\ExceptionInterface) { ... }
+ */
+
+interface ExceptionInterface extends \CodeIgniter\Exceptions\ExceptionInterface
+{
+
+}

system/Database/Migration.php

@@ -0,0 +1,110 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Class Migration
+ */
+abstract class Migration
+{
+
+	/**
+	 * The name of the database group to use.
+	 *
+	 * @var string
+	 */
+	protected $DBGroup;
+
+	/**
+	 * Database Connection instance
+	 *
+	 * @var BaseConnection
+	 */
+	protected $db;
+
+	/**
+	 * Database Forge instance.
+	 *
+	 * @var Forge
+	 */
+	protected $forge;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor.
+	 *
+	 * @param \CodeIgniter\Database\Forge $forge
+	 */
+	public function __construct(Forge $forge = null)
+	{
+		$this->forge = ! is_null($forge) ? $forge : \Config\Database::forge($this->DBGroup ?? config('Database')->defaultGroup);
+
+		$this->db = $this->forge->getConnection();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the database group name this migration uses.
+	 *
+	 * @return string
+	 */
+	public function getDBGroup(): ?string
+	{
+		return $this->DBGroup;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Perform a migration step.
+	 */
+	abstract public function up();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Revert a migration step.
+	 */
+	abstract public function down();
+
+	//--------------------------------------------------------------------
+}

system/Database/MySQLi/Builder.php

@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+use CodeIgniter\Database\BaseBuilder;
+
+/**
+ * Builder for MySQLi
+ */
+class Builder extends BaseBuilder
+{
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var string
+	 */
+	protected $escapeChar = '`';
+
+	/**
+	 * FROM tables
+	 *
+	 * Groups tables in FROM clauses if needed, so there is no confusion
+	 * about operator precedence.
+	 *
+	 * Note: This is only used (and overridden) by MySQL.
+	 *
+	 * @return string
+	 */
+	protected function _fromTables(): string
+	{
+		if (! empty($this->QBJoin) && count($this->QBFrom) > 1)
+		{
+			return '(' . implode(', ', $this->QBFrom) . ')';
+		}
+
+		return implode(', ', $this->QBFrom);
+	}
+
+}

system/Database/MySQLi/Connection.php

@@ -0,0 +1,732 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+use CodeIgniter\Database\BaseConnection;
+use CodeIgniter\Database\ConnectionInterface;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Connection for MySQLi
+ */
+class Connection extends BaseConnection implements ConnectionInterface
+{
+	/**
+	 * Database driver
+	 *
+	 * @var string
+	 */
+	public $DBDriver = 'MySQLi';
+	/**
+	 * DELETE hack flag
+	 *
+	 * Whether to use the MySQL "delete hack" which allows the number
+	 * of affected rows to be shown. Uses a preg_replace when enabled,
+	 * adding a bit more processing to all queries.
+	 *
+	 * @var boolean
+	 */
+	public $deleteHack = true;
+	// --------------------------------------------------------------------
+	/**
+	 * Identifier escape character
+	 *
+	 * @var string
+	 */
+	public $escapeChar = '`';
+	// --------------------------------------------------------------------
+	/**
+	 * MySQLi object
+	 *
+	 * Has to be preserved without being assigned to $conn_id.
+	 *
+	 * @var \MySQLi
+	 */
+	public $mysqli;
+	//--------------------------------------------------------------------
+
+	/**
+	 * Connect to the database.
+	 *
+	 * @param boolean $persistent
+	 *
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function connect(bool $persistent = false)
+	{
+		// Do we have a socket path?
+		if ($this->hostname[0] === '/')
+		{
+			$hostname = null;
+			$port     = null;
+			$socket   = $this->hostname;
+		}
+		else
+		{
+			$hostname = ($persistent === true) ? 'p:' . $this->hostname : $this->hostname;
+			$port     = empty($this->port) ? null : $this->port;
+			$socket   = null;
+		}
+
+		$client_flags = ($this->compress === true) ? MYSQLI_CLIENT_COMPRESS : 0;
+		$this->mysqli = mysqli_init();
+
+		mysqli_report(MYSQLI_REPORT_ALL & ~MYSQLI_REPORT_INDEX);
+
+		$this->mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 10);
+
+		if (isset($this->strictOn))
+		{
+			if ($this->strictOn)
+			{
+				$this->mysqli->options(MYSQLI_INIT_COMMAND,
+					'SET SESSION sql_mode = CONCAT(@@sql_mode, ",", "STRICT_ALL_TABLES")');
+			}
+			else
+			{
+				$this->mysqli->options(MYSQLI_INIT_COMMAND, 'SET SESSION sql_mode =
+						REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
+												@@sql_mode,
+												"STRICT_ALL_TABLES,", ""),
+											",STRICT_ALL_TABLES", ""),
+										"STRICT_ALL_TABLES", ""),
+									"STRICT_TRANS_TABLES,", ""),
+								",STRICT_TRANS_TABLES", ""),
+							"STRICT_TRANS_TABLES", "")'
+				);
+			}
+		}
+
+		if (is_array($this->encrypt))
+		{
+			$ssl                                                  = [];
+			empty($this->encrypt['ssl_key']) || $ssl['key']       = $this->encrypt['ssl_key'];
+			empty($this->encrypt['ssl_cert']) || $ssl['cert']     = $this->encrypt['ssl_cert'];
+			empty($this->encrypt['ssl_ca']) || $ssl['ca']         = $this->encrypt['ssl_ca'];
+			empty($this->encrypt['ssl_capath']) || $ssl['capath'] = $this->encrypt['ssl_capath'];
+			empty($this->encrypt['ssl_cipher']) || $ssl['cipher'] = $this->encrypt['ssl_cipher'];
+
+			if (! empty($ssl))
+			{
+				if (isset($this->encrypt['ssl_verify']))
+				{
+					if ($this->encrypt['ssl_verify'])
+					{
+						defined('MYSQLI_OPT_SSL_VERIFY_SERVER_CERT') &&
+						$this->mysqli->options(MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, true);
+					}
+					// Apparently (when it exists), setting MYSQLI_OPT_SSL_VERIFY_SERVER_CERT
+					// to FALSE didn't do anything, so PHP 5.6.16 introduced yet another
+					// constant ...
+					//
+					// https://secure.php.net/ChangeLog-5.php#5.6.16
+					// https://bugs.php.net/bug.php?id=68344
+					elseif (defined('MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT') && version_compare($this->mysqli->client_info, '5.6', '>='))
+					{
+						$client_flags += MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT;
+					}
+				}
+
+				$client_flags += MYSQLI_CLIENT_SSL;
+				$this->mysqli->ssl_set(
+					$ssl['key'] ?? null, $ssl['cert'] ?? null, $ssl['ca'] ?? null,
+					$ssl['capath'] ?? null, $ssl['cipher'] ?? null
+				);
+			}
+		}
+
+		try
+		{
+			if ($this->mysqli->real_connect($hostname, $this->username, $this->password,
+				$this->database, $port, $socket, $client_flags)
+			)
+			{
+				// Prior to version 5.7.3, MySQL silently downgrades to an unencrypted connection if SSL setup fails
+				if (($client_flags & MYSQLI_CLIENT_SSL) && version_compare($this->mysqli->client_info, '5.7.3', '<=')
+					&& empty($this->mysqli->query("SHOW STATUS LIKE 'ssl_cipher'")
+										  ->fetch_object()->Value)
+				)
+				{
+					$this->mysqli->close();
+					$message = 'MySQLi was configured for an SSL connection, but got an unencrypted connection instead!';
+					log_message('error', $message);
+
+					if ($this->DBDebug)
+					{
+						throw new DatabaseException($message);
+					}
+
+					return false;
+				}
+
+				if (! $this->mysqli->set_charset($this->charset))
+				{
+					log_message('error',
+						"Database: Unable to set the configured connection charset ('{$this->charset}').");
+					$this->mysqli->close();
+
+					if ($this->db->debug)
+					{
+						throw new DatabaseException('Unable to set client connection character set: ' . $this->charset);
+					}
+
+					return false;
+				}
+
+				return $this->mysqli;
+			}
+		}
+		catch (\Throwable $e)
+		{
+			// Clean sensitive information from errors.
+			$msg = $e->getMessage();
+
+			$msg = str_replace($this->username, '****', $msg);
+			$msg = str_replace($this->password, '****', $msg);
+
+			throw new \mysqli_sql_exception($msg, $e->getCode(), $e);
+		}
+
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Keep or establish the connection if no queries have been sent for
+	 * a length of time exceeding the server's idle timeout.
+	 *
+	 * @return void
+	 */
+	public function reconnect()
+	{
+		$this->close();
+		$this->initialize();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Close the database connection.
+	 *
+	 * @return void
+	 */
+	protected function _close()
+	{
+		$this->connID->close();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Select a specific database table to use.
+	 *
+	 * @param string $databaseName
+	 *
+	 * @return boolean
+	 */
+	public function setDatabase(string $databaseName): bool
+	{
+		if ($databaseName === '')
+		{
+			$databaseName = $this->database;
+		}
+
+		if (empty($this->connID))
+		{
+			$this->initialize();
+		}
+
+		if ($this->connID->select_db($databaseName))
+		{
+			$this->database = $databaseName;
+
+			return true;
+		}
+
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a string containing the version of the database being used.
+	 *
+	 * @return string
+	 */
+	public function getVersion(): string
+	{
+		if (isset($this->dataCache['version']))
+		{
+			return $this->dataCache['version'];
+		}
+
+		if (empty($this->mysqli))
+		{
+			$this->initialize();
+		}
+
+		return $this->dataCache['version'] = $this->mysqli->server_info;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Executes the query against the database.
+	 *
+	 * @param string $sql
+	 *
+	 * @return mixed
+	 */
+	public function execute(string $sql)
+	{
+		while ($this->connID->more_results())
+		{
+			$this->connID->next_result();
+			if ($res = $this->connID->store_result())
+			{
+				$res->free();
+			}
+		}
+
+		return $this->connID->query($this->prepQuery($sql));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep the query
+	 *
+	 * If needed, each database adapter can prep the query string
+	 *
+	 * @param string $sql an SQL query
+	 *
+	 * @return string
+	 */
+	protected function prepQuery(string $sql): string
+	{
+		// mysqli_affected_rows() returns 0 for "DELETE FROM TABLE" queries. This hack
+		// modifies the query so that it a proper number of affected rows is returned.
+		if ($this->deleteHack === true && preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))
+		{
+			return trim($sql) . ' WHERE 1=1';
+		}
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the total number of rows affected by this query.
+	 *
+	 * @return integer
+	 */
+	public function affectedRows(): int
+	{
+		return $this->connID->affected_rows ?? 0;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform-dependant string escape
+	 *
+	 * @param  string $str
+	 * @return string
+	 */
+	protected function _escapeString(string $str): string
+	{
+		if (is_bool($str))
+		{
+			return $str;
+		}
+
+		if (! $this->connID)
+		{
+			$this->initialize();
+		}
+
+		return $this->connID->real_escape_string($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Escape Like String Direct
+	 * There are a few instances where MySQLi queries cannot take the
+	 * additional "ESCAPE x" parameter for specifying the escape character
+	 * in "LIKE" strings, and this handles those directly with a backslash.
+	 *
+	 * @param  string|string[] $str Input string
+	 * @return string|string[]
+	 */
+	public function escapeLikeStringDirect($str)
+	{
+		if (is_array($str))
+		{
+			foreach ($str as $key => $val)
+			{
+				$str[$key] = $this->escapeLikeStringDirect($val);
+			}
+
+			return $str;
+		}
+
+		$str = $this->_escapeString($str);
+
+		// Escape LIKE condition wildcards
+		return str_replace([
+			$this->likeEscapeChar,
+			'%',
+			'_',
+		], [
+			'\\' . $this->likeEscapeChar,
+			'\\' . '%',
+			'\\' . '_',
+		], $str
+		);
+
+		return $str;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates the SQL for listing tables in a platform-dependent manner.
+	 * Uses escapeLikeStringDirect().
+	 *
+	 * @param boolean $prefixLimit
+	 *
+	 * @return string
+	 */
+	protected function _listTables(bool $prefixLimit = false): string
+	{
+		$sql = 'SHOW TABLES FROM ' . $this->escapeIdentifiers($this->database);
+
+		if ($prefixLimit !== false && $this->DBPrefix !== '')
+		{
+			return $sql . " LIKE '" . $this->escapeLikeStringDirect($this->DBPrefix) . "%'";
+		}
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates a platform-specific query string so that the column names can be fetched.
+	 *
+	 * @param string $table
+	 *
+	 * @return string
+	 */
+	protected function _listColumns(string $table = ''): string
+	{
+		return 'SHOW COLUMNS FROM ' . $this->protectIdentifiers($table, true, null, false);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with field data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _fieldData(string $table): array
+	{
+		$table = $this->protectIdentifiers($table, true, null, false);
+
+		if (($query = $this->query('SHOW COLUMNS FROM ' . $table)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetFieldData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		for ($i = 0, $c = count($query); $i < $c; $i++)
+		{
+			$retVal[$i]       = new \stdClass();
+			$retVal[$i]->name = $query[$i]->Field;
+
+			sscanf($query[$i]->Type, '%[a-z](%d)', $retVal[$i]->type, $retVal[$i]->max_length);
+
+			$retVal[$i]->default     = $query[$i]->Default;
+			$retVal[$i]->primary_key = (int)($query[$i]->Key === 'PRI');
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with index data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 * @throws \LogicException
+	 */
+	public function _indexData(string $table): array
+	{
+		$table = $this->protectIdentifiers($table, true, null, false);
+
+		if (($query = $this->query('SHOW INDEX FROM ' . $table)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetIndexData'));
+		}
+
+		if (! $indexes = $query->getResultArray())
+		{
+			return [];
+		}
+
+		$keys = [];
+
+		foreach ($indexes as $index)
+		{
+			if (empty($keys[$index['Key_name']]))
+			{
+				$keys[$index['Key_name']]       = new \stdClass();
+				$keys[$index['Key_name']]->name = $index['Key_name'];
+
+				if ($index['Key_name'] === 'PRIMARY')
+				{
+					$type = 'PRIMARY';
+				}
+				elseif ($index['Index_type'] === 'FULLTEXT')
+				{
+					$type = 'FULLTEXT';
+				}
+				elseif ($index['Non_unique'])
+				{
+					if ($index['Index_type'] === 'SPATIAL')
+					{
+						$type = 'SPATIAL';
+					}
+					else
+					{
+						$type = 'INDEX';
+					}
+				}
+				else
+				{
+					$type = 'UNIQUE';
+				}
+
+				$keys[$index['Key_name']]->type = $type;
+			}
+
+			$keys[$index['Key_name']]->fields[] = $index['Column_name'];
+		}
+
+		return $keys;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with Foreign key data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _foreignKeyData(string $table): array
+	{
+		$sql = '
+                    SELECT
+                        tc.CONSTRAINT_NAME,
+                        tc.TABLE_NAME,
+                        kcu.COLUMN_NAME,
+                        rc.REFERENCED_TABLE_NAME,
+                        kcu.REFERENCED_COLUMN_NAME
+                    FROM information_schema.TABLE_CONSTRAINTS AS tc
+                    INNER JOIN information_schema.REFERENTIAL_CONSTRAINTS AS rc
+                        ON tc.CONSTRAINT_NAME = rc.CONSTRAINT_NAME
+                    INNER JOIN information_schema.KEY_COLUMN_USAGE AS kcu
+                        ON tc.CONSTRAINT_NAME = kcu.CONSTRAINT_NAME
+                    WHERE
+                        tc.CONSTRAINT_TYPE = ' . $this->escape('FOREIGN KEY') . ' AND
+                        tc.TABLE_SCHEMA = ' . $this->escape($this->database) . ' AND
+                        tc.TABLE_NAME = ' . $this->escape($table);
+
+		if (($query = $this->query($sql)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetForeignKeyData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		foreach ($query as $row)
+		{
+			$obj                      = new \stdClass();
+			$obj->constraint_name     = $row->CONSTRAINT_NAME;
+			$obj->table_name          = $row->TABLE_NAME;
+			$obj->column_name         = $row->COLUMN_NAME;
+			$obj->foreign_table_name  = $row->REFERENCED_TABLE_NAME;
+			$obj->foreign_column_name = $row->REFERENCED_COLUMN_NAME;
+
+			$retVal[] = $obj;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to disable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _disableForeignKeyChecks()
+	{
+		return 'SET FOREIGN_KEY_CHECKS=0';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to enable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _enableForeignKeyChecks()
+	{
+		return 'SET FOREIGN_KEY_CHECKS=1';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the last error code and message.
+	 *
+	 * Must return an array with keys 'code' and 'message':
+	 *
+	 *  return ['code' => null, 'message' => null);
+	 *
+	 * @return array
+	 */
+	public function error(): array
+	{
+		if (! empty($this->mysqli->connect_errno))
+		{
+			return [
+				'code'    => $this->mysqli->connect_errno,
+				'message' => $this->mysqli->connect_error,
+			];
+		}
+
+		return [
+			'code'    => $this->connID->errno,
+			'message' => $this->connID->error,
+		];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Insert ID
+	 *
+	 * @return integer
+	 */
+	public function insertID(): int
+	{
+		return $this->connID->insert_id;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transBegin(): bool
+	{
+		$this->connID->autocommit(false);
+
+		return $this->connID->begin_transaction();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transCommit(): bool
+	{
+		if ($this->connID->commit())
+		{
+			$this->connID->autocommit(true);
+
+			return true;
+		}
+
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transRollback(): bool
+	{
+		if ($this->connID->rollback())
+		{
+			$this->connID->autocommit(true);
+
+			return true;
+		}
+
+		return false;
+	}
+	//--------------------------------------------------------------------
+}

system/Database/MySQLi/Forge.php

@@ -0,0 +1,279 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+/**
+ * Forge for MySQLi
+ */
+class Forge extends \CodeIgniter\Database\Forge
+{
+
+	/**
+	 * CREATE DATABASE statement
+	 *
+	 * @var string
+	 */
+	protected $createDatabaseStr = 'CREATE DATABASE %s CHARACTER SET %s COLLATE %s';
+
+	/**
+	 * CREATE DATABASE IF statement
+	 *
+	 * @var string
+	 */
+	protected $createDatabaseIfStr = 'CREATE DATABASE IF NOT EXISTS %s CHARACTER SET %s COLLATE %s';
+
+	/**
+	 * DROP CONSTRAINT statement
+	 *
+	 * @var string
+	 */
+	protected $dropConstraintStr = 'ALTER TABLE %s DROP FOREIGN KEY %s';
+
+	/**
+	 * CREATE TABLE keys flag
+	 *
+	 * Whether table keys are created from within the
+	 * CREATE TABLE statement.
+	 *
+	 * @var boolean
+	 */
+	protected $createTableKeys = true;
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var array
+	 */
+	protected $_unsigned = [
+		'TINYINT',
+		'SMALLINT',
+		'MEDIUMINT',
+		'INT',
+		'INTEGER',
+		'BIGINT',
+		'REAL',
+		'DOUBLE',
+		'DOUBLE PRECISION',
+		'FLOAT',
+		'DECIMAL',
+		'NUMERIC',
+	];
+
+	/**
+	 * Table Options list which required to be quoted
+	 *
+	 * @var array
+	 */
+	protected $_quoted_table_options = [
+		'COMMENT',
+		'COMPRESSION',
+		'CONNECTION',
+		'DATA DIRECTORY',
+		'INDEX DIRECTORY',
+		'ENCRYPTION',
+		'PASSWORD',
+	];
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var string
+	 */
+	protected $_null = 'NULL';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * CREATE TABLE attributes
+	 *
+	 * @param  array $attributes Associative array of table attributes
+	 * @return string
+	 */
+	protected function _createTableAttributes(array $attributes): string
+	{
+		$sql = '';
+
+		foreach (array_keys($attributes) as $key)
+		{
+			if (is_string($key))
+			{
+				$sql .= ' ' . strtoupper($key) . ' = ';
+
+				if (in_array(strtoupper($key), $this->_quoted_table_options))
+				{
+					$sql .= $this->db->escape($attributes[$key]);
+				}
+				else
+				{
+					$sql .= $this->db->escapeString($attributes[$key]);
+				}
+			}
+		}
+
+		if (! empty($this->db->charset) && ! strpos($sql, 'CHARACTER SET') && ! strpos($sql, 'CHARSET'))
+		{
+			$sql .= ' DEFAULT CHARACTER SET = ' . $this->db->escapeString($this->db->charset);
+		}
+
+		if (! empty($this->db->DBCollat) && ! strpos($sql, 'COLLATE'))
+		{
+			$sql .= ' COLLATE = ' . $this->db->escapeString($this->db->DBCollat);
+		}
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param  string $alter_type ALTER type
+	 * @param  string $table      Table name
+	 * @param  mixed  $field      Column definition
+	 * @return string|string[]
+	 */
+	protected function _alterTable(string $alter_type, string $table, $field)
+	{
+		if ($alter_type === 'DROP')
+		{
+			return parent::_alterTable($alter_type, $table, $field);
+		}
+
+		$sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
+		foreach ($field as $i => $data)
+		{
+			if ($data['_literal'] !== false)
+			{
+				$field[$i] = ($alter_type === 'ADD') ? "\n\tADD " . $data['_literal'] : "\n\tMODIFY " . $data['_literal'];
+			}
+			else
+			{
+				if ($alter_type === 'ADD')
+				{
+					$field[$i]['_literal'] = "\n\tADD ";
+				}
+				else
+				{
+					$field[$i]['_literal'] = empty($data['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
+				}
+
+				$field[$i] = $field[$i]['_literal'] . $this->_processColumn($field[$i]);
+			}
+		}
+
+		return [$sql . implode(',', $field)];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param  array $field
+	 * @return string
+	 */
+	protected function _processColumn(array $field): string
+	{
+		$extra_clause = isset($field['after']) ? ' AFTER ' . $this->db->escapeIdentifiers($field['after']) : '';
+
+		if (empty($extra_clause) && isset($field['first']) && $field['first'] === true)
+		{
+			$extra_clause = ' FIRST';
+		}
+
+		return $this->db->escapeIdentifiers($field['name'])
+				. (empty($field['new_name']) ? '' : ' ' . $this->db->escapeIdentifiers($field['new_name']))
+				. ' ' . $field['type'] . $field['length']
+				. $field['unsigned']
+				. $field['null']
+				. $field['default']
+				. $field['auto_increment']
+				. $field['unique']
+				. (empty($field['comment']) ? '' : ' COMMENT ' . $field['comment'])
+				. $extra_clause;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Process indexes
+	 *
+	 * @param  string $table (ignored)
+	 * @return string
+	 */
+	protected function _processIndexes(string $table): string
+	{
+		$sql = '';
+
+		for ($i = 0, $c = count($this->keys); $i < $c; $i ++)
+		{
+			if (is_array($this->keys[$i]))
+			{
+				for ($i2 = 0, $c2 = count($this->keys[$i]); $i2 < $c2; $i2 ++)
+				{
+					if (! isset($this->fields[$this->keys[$i][$i2]]))
+					{
+						unset($this->keys[$i][$i2]);
+						continue;
+					}
+				}
+			}
+			elseif (! isset($this->fields[$this->keys[$i]]))
+			{
+				unset($this->keys[$i]);
+				continue;
+			}
+
+			is_array($this->keys[$i]) || $this->keys[$i] = [$this->keys[$i]];
+
+			$unique = in_array($i, $this->uniqueKeys) ? 'UNIQUE ' : '';
+
+			$sql .= ",\n\t{$unique}KEY " . $this->db->escapeIdentifiers(implode('_', $this->keys[$i]))
+				. ' (' . implode(', ', $this->db->escapeIdentifiers($this->keys[$i])) . ')';
+		}
+
+		$this->keys = [];
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/MySQLi/PreparedQuery.php

@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+use CodeIgniter\Database\PreparedQueryInterface;
+use CodeIgniter\Database\BasePreparedQuery;
+
+/**
+ * Prepared query for MySQLi
+ */
+class PreparedQuery extends BasePreparedQuery implements PreparedQueryInterface
+{
+
+	/**
+	 * Prepares the query against the database, and saves the connection
+	 * info necessary to execute the query later.
+	 *
+	 * NOTE: This version is based on SQL code. Child classes should
+	 * override this method.
+	 *
+	 * @param string $sql
+	 * @param array  $options Passed to the connection's prepare statement.
+	 *                        Unused in the MySQLi driver.
+	 *
+	 * @return mixed
+	 */
+	public function _prepare(string $sql, array $options = [])
+	{
+		// Mysqli driver doesn't like statements
+		// with terminating semicolons.
+		$sql = rtrim($sql, ';');
+
+		if (! $this->statement = $this->db->mysqli->prepare($sql))
+		{
+			$this->errorCode   = $this->db->mysqli->errno;
+			$this->errorString = $this->db->mysqli->error;
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Takes a new set of data and runs it against the currently
+	 * prepared query. Upon success, will return a Results object.
+	 *
+	 * @param array $data
+	 *
+	 * @return boolean
+	 */
+	public function _execute(array $data): bool
+	{
+		if (is_null($this->statement))
+		{
+			throw new \BadMethodCallException('You must call prepare before trying to execute a prepared statement.');
+		}
+
+		// First off -bind the parameters
+		$bindTypes = '';
+
+		// Determine the type string
+		foreach ($data as $item)
+		{
+			if (is_integer($item))
+			{
+				$bindTypes .= 'i';
+			}
+			elseif (is_numeric($item))
+			{
+				$bindTypes .= 'd';
+			}
+			else
+			{
+				$bindTypes .= 's';
+			}
+		}
+
+		// Bind it
+		$this->statement->bind_param($bindTypes, ...$data);
+
+		$success = $this->statement->execute();
+
+		return $success;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result object for the prepared query.
+	 *
+	 * @return mixed
+	 */
+	public function _getResult()
+	{
+		return $this->statement->get_result();
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/MySQLi/Result.php

@@ -0,0 +1,173 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+use CodeIgniter\Database\BaseResult;
+use CodeIgniter\Database\ResultInterface;
+use CodeIgniter\Entity;
+
+/**
+ * Result for MySQLi
+ */
+class Result extends BaseResult implements ResultInterface
+{
+
+	/**
+	 * Gets the number of fields in the result set.
+	 *
+	 * @return integer
+	 */
+	public function getFieldCount(): int
+	{
+		return $this->resultID->field_count;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of column names in the result set.
+	 *
+	 * @return array
+	 */
+	public function getFieldNames(): array
+	{
+		$fieldNames = [];
+		$this->resultID->field_seek(0);
+		while ($field = $this->resultID->fetch_field())
+		{
+			$fieldNames[] = $field->name;
+		}
+
+		return $fieldNames;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of objects representing field meta-data.
+	 *
+	 * @return array
+	 */
+	public function getFieldData(): array
+	{
+		$retVal    = [];
+		$fieldData = $this->resultID->fetch_fields();
+
+		foreach ($fieldData as $i => $data)
+		{
+			$retVal[$i]              = new \stdClass();
+			$retVal[$i]->name        = $data->name;
+			$retVal[$i]->type        = $data->type;
+			$retVal[$i]->max_length  = $data->max_length;
+			$retVal[$i]->primary_key = (int) ($data->flags & 2);
+			$retVal[$i]->default     = $data->def;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Frees the current result.
+	 *
+	 * @return void
+	 */
+	public function freeResult()
+	{
+		if (is_object($this->resultID))
+		{
+			$this->resultID->free();
+			$this->resultID = false;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Moves the internal pointer to the desired offset. This is called
+	 * internally before fetching results to make sure the result set
+	 * starts at zero.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function dataSeek(int $n = 0)
+	{
+		return $this->resultID->data_seek($n);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an array.
+	 *
+	 * Overridden by driver classes.
+	 *
+	 * @return mixed
+	 */
+	protected function fetchAssoc()
+	{
+		return $this->resultID->fetch_assoc();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an object.
+	 *
+	 * Overridden by child classes.
+	 *
+	 * @param string $className
+	 *
+	 * @return object|boolean|Entity
+	 */
+	protected function fetchObject(string $className = 'stdClass')
+	{
+		if (is_subclass_of($className, Entity::class))
+		{
+			return empty($data = $this->fetchAssoc()) ? false : (new $className())->setAttributes($data);
+		}
+		return $this->resultID->fetch_object($className);
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/MySQLi/Utils.php

@@ -0,0 +1,80 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\MySQLi;
+
+use CodeIgniter\Database\BaseUtils;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Utils for MySQLi
+ */
+class Utils extends BaseUtils
+{
+
+	/**
+	 * List databases statement
+	 *
+	 * @var string
+	 */
+	protected $listDatabases = 'SHOW DATABASES';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var string
+	 */
+	protected $optimizeTable = 'OPTIMIZE TABLE %s';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform dependent version of the backup function.
+	 *
+	 * @param array|null $prefs
+	 *
+	 * @return mixed
+	 */
+	public function _backup(array $prefs = null)
+	{
+		throw new DatabaseException('Unsupported feature of the database platform you are using.');
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Postgre/Builder.php

@@ -0,0 +1,368 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+use CodeIgniter\Database\BaseBuilder;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Builder for Postgre
+ */
+class Builder extends BaseBuilder
+{
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var array
+	 */
+	protected $randomKeyword = [
+		'RANDOM()',
+	];
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * ORDER BY
+	 *
+	 * @param string  $orderBy
+	 * @param string  $direction ASC, DESC or RANDOM
+	 * @param boolean $escape
+	 *
+	 * @return BaseBuilder
+	 */
+	public function orderBy(string $orderBy, string $direction = '', bool $escape = null)
+	{
+		$direction = strtoupper(trim($direction));
+		if ($direction === 'RANDOM')
+		{
+			if (! is_float($orderBy) && ctype_digit((string) $orderBy))
+			{
+				$orderBy = (float) ($orderBy > 1 ? "0.{$orderBy}" : $orderBy);
+			}
+
+			if (is_float($orderBy))
+			{
+				$this->db->simpleQuery("SET SEED {$orderBy}");
+			}
+
+			$orderBy   = $this->randomKeyword[0];
+			$direction = '';
+			$escape    = false;
+		}
+
+		return parent::orderBy($orderBy, $direction, $escape);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Increments a numeric column by the specified value.
+	 *
+	 * @param string  $column
+	 * @param integer $value
+	 *
+	 * @return mixed
+	 */
+	public function increment(string $column, int $value = 1)
+	{
+		$column = $this->db->protectIdentifiers($column);
+
+		$sql = $this->_update($this->QBFrom[0], [$column => "to_number({$column}, '9999999') + {$value}"]);
+
+		return $this->db->query($sql, $this->binds, false);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Decrements a numeric column by the specified value.
+	 *
+	 * @param string  $column
+	 * @param integer $value
+	 *
+	 * @return mixed
+	 */
+	public function decrement(string $column, int $value = 1)
+	{
+		$column = $this->db->protectIdentifiers($column);
+
+		$sql = $this->_update($this->QBFrom[0], [$column => "to_number({$column}, '9999999') - {$value}"]);
+
+		return $this->db->query($sql, $this->binds, false);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Replace
+	 *
+	 * Compiles an replace into string and runs the query.
+	 * Because PostgreSQL doesn't support the replace into command,
+	 * we simply do a DELETE and an INSERT on the first key/value
+	 * combo, assuming that it's either the primary key or a unique key.
+	 *
+	 * @param array $set An associative array of insert values
+	 *
+	 * @return   mixed
+	 * @throws   DatabaseException
+	 * @internal param true $bool returns the generated SQL, false executes the query.
+	 */
+	public function replace(array $set = null)
+	{
+		if ($set !== null)
+		{
+			$this->set($set);
+		}
+
+		if (! $this->QBSet)
+		{
+			if (CI_DEBUG)
+			{
+				throw new DatabaseException('You must use the "set" method to update an entry.');
+			}
+			return false;
+		}
+
+		$table = $this->QBFrom[0];
+
+		$set = $this->binds;
+
+		// We need to grab out the actual values from
+		// the way binds are stored with escape flag.
+		array_walk($set, function (&$item) {
+			$item = $item[0];
+		});
+
+		$keys   = array_keys($set);
+		$values = array_values($set);
+
+		$builder = $this->db->table($table);
+		$exists  = $builder->where("$keys[0] = $values[0]", null, false)->get()->getFirstRow();
+
+		if (empty($exists))
+		{
+			$result = $builder->insert($set);
+		}
+		else
+		{
+			array_pop($set);
+			$result = $builder->update($set, "$keys[0] = $values[0]");
+		}
+
+		unset($builder);
+		$this->resetWrite();
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Delete
+	 *
+	 * Compiles a delete string and runs the query
+	 *
+	 * @param mixed   $where
+	 * @param integer $limit
+	 * @param boolean $reset_data
+	 *
+	 * @return   mixed
+	 * @throws   DatabaseException
+	 * @internal param the $mixed where clause
+	 * @internal param the $mixed limit clause
+	 * @internal param $bool
+	 */
+	public function delete($where = '', int $limit = null, bool $reset_data = true)
+	{
+		if (! empty($limit) || ! empty($this->QBLimit))
+		{
+			throw new DatabaseException('PostgreSQL does not allow LIMITs on DELETE queries.');
+		}
+
+		return parent::delete($where, $limit, $reset_data);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * LIMIT string
+	 *
+	 * Generates a platform-specific LIMIT clause.
+	 *
+	 * @param string $sql SQL Query
+	 *
+	 * @return string
+	 */
+	protected function _limit(string $sql): string
+	{
+		return $sql . ' LIMIT ' . $this->QBLimit . ($this->QBOffset ? " OFFSET {$this->QBOffset}" : '');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Update statement
+	 *
+	 * Generates a platform-specific update string from the supplied data
+	 *
+	 * @param string $table
+	 * @param array  $values
+	 *
+	 * @return   string
+	 * @throws   DatabaseException
+	 * @internal param the $string table name
+	 * @internal param the $array update data
+	 */
+	protected function _update(string $table, array $values): string
+	{
+		if (! empty($this->QBLimit))
+		{
+			throw new DatabaseException('Postgres does not support LIMITs with UPDATE queries.');
+		}
+
+		$this->QBOrderBy = [];
+		return parent::_update($table, $values);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Update_Batch statement
+	 *
+	 * Generates a platform-specific batch update string from the supplied data
+	 *
+	 * @param string $table  Table name
+	 * @param array  $values Update data
+	 * @param string $index  WHERE key
+	 *
+	 * @return string
+	 */
+	protected function _updateBatch(string $table, array $values, string $index): string
+	{
+		$ids = [];
+		foreach ($values as $key => $val)
+		{
+			$ids[] = $val[$index];
+
+			foreach (array_keys($val) as $field)
+			{
+				if ($field !== $index)
+				{
+					$final[$field][] = "WHEN {$val[$index]} THEN {$val[$field]}";
+				}
+			}
+		}
+
+		$cases = '';
+		foreach ($final as $k => $v)
+		{
+			$cases .= "{$k} = (CASE {$index}\n"
+					. implode("\n", $v)
+					. "\nELSE {$k} END), ";
+		}
+
+		$this->where("{$index} IN(" . implode(',', $ids) . ')', null, false);
+
+		return "UPDATE {$table} SET " . substr($cases, 0, -2) . $this->compileWhereHaving('QBWhere');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Delete statement
+	 *
+	 * Generates a platform-specific delete string from the supplied data
+	 *
+	 * @param string $table The table name
+	 *
+	 * @return string
+	 */
+	protected function _delete(string $table): string
+	{
+		$this->QBLimit = false;
+		return parent::_delete($table);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Truncate statement
+	 *
+	 * Generates a platform-specific truncate string from the supplied data
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
+	 *
+	 * @param string $table The table name
+	 *
+	 * @return string
+	 */
+	protected function _truncate(string $table): string
+	{
+		return 'TRUNCATE ' . $table . ' RESTART IDENTITY';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform independent LIKE statement builder.
+	 *
+	 * In PostgreSQL, the ILIKE operator will perform case insensitive
+	 * searches according to the current locale.
+	 *
+	 * @see https://www.postgresql.org/docs/9.2/static/functions-matching.html
+	 *
+	 * @param string  $prefix
+	 * @param string  $column
+	 * @param string  $not
+	 * @param string  $bind
+	 * @param boolean $insensitiveSearch
+	 *
+	 * @return string     $like_statement
+	 */
+	public function _like_statement(string $prefix = null, string $column, string $not = null, string $bind, bool $insensitiveSearch = false): string
+	{
+		$op = $insensitiveSearch === true ? 'ILIKE' : 'LIKE';
+
+		return "{$prefix} {$column} {$not} {$op} :{$bind}:";
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Postgre/Connection.php

@@ -0,0 +1,614 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+use CodeIgniter\Database\BaseConnection;
+use CodeIgniter\Database\ConnectionInterface;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Connection for Postgre
+ */
+class Connection extends BaseConnection implements ConnectionInterface
+{
+
+	/**
+	 * Database driver
+	 *
+	 * @var string
+	 */
+	public $DBDriver = 'postgre';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Database schema
+	 *
+	 * @var string
+	 */
+	public $schema = 'public';
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var string
+	 */
+	public $escapeChar = '"';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Connect to the database.
+	 *
+	 * @param  boolean $persistent
+	 * @return mixed
+	 */
+	public function connect(bool $persistent = false)
+	{
+		if (empty($this->DSN))
+		{
+			$this->buildDSN();
+		}
+
+		// Strip pgsql if exists
+		if (mb_strpos($this->DSN, 'pgsql:') === 0)
+		{
+			$this->DSN = mb_substr($this->DSN, 6);
+		}
+
+		// Convert semicolons to spaces.
+		$this->DSN = str_replace(';', ' ', $this->DSN);
+
+		$this->connID = $persistent === true ? pg_pconnect($this->DSN) : pg_connect($this->DSN);
+
+		if ($this->connID !== false)
+		{
+			if ($persistent === true && pg_connection_status($this->connID) === PGSQL_CONNECTION_BAD && pg_ping($this->connID) === false
+			)
+			{
+				return false;
+			}
+
+			empty($this->schema) || $this->simpleQuery("SET search_path TO {$this->schema},public");
+
+			if ($this->setClientEncoding($this->charset) === false)
+			{
+				return false;
+			}
+		}
+
+		return $this->connID;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Keep or establish the connection if no queries have been sent for
+	 * a length of time exceeding the server's idle timeout.
+	 *
+	 * @return void
+	 */
+	public function reconnect()
+	{
+		if (pg_ping($this->connID) === false)
+		{
+			$this->connID = false;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Close the database connection.
+	 *
+	 * @return void
+	 */
+	protected function _close()
+	{
+		pg_close($this->connID);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Select a specific database table to use.
+	 *
+	 * @param string $databaseName
+	 *
+	 * @return boolean
+	 */
+	public function setDatabase(string $databaseName): bool
+	{
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a string containing the version of the database being used.
+	 *
+	 * @return string
+	 */
+	public function getVersion(): string
+	{
+		if (isset($this->dataCache['version']))
+		{
+			return $this->dataCache['version'];
+		}
+
+		if (! $this->connID || ( $pgVersion = pg_version($this->connID)) === false)
+		{
+			$this->initialize();
+		}
+
+		return isset($pgVersion['server']) ? $this->dataCache['version'] = $pgVersion['server'] : false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Executes the query against the database.
+	 *
+	 * @param string $sql
+	 *
+	 * @return resource
+	 */
+	public function execute(string $sql)
+	{
+		return pg_query($this->connID, $sql);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the total number of rows affected by this query.
+	 *
+	 * @return integer
+	 */
+	public function affectedRows(): int
+	{
+		return pg_affected_rows($this->resultID);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * "Smart" Escape String
+	 *
+	 * Escapes data based on type
+	 *
+	 * @param  mixed $str
+	 * @return mixed
+	 */
+	public function escape($str)
+	{
+		if (! $this->connID)
+		{
+			$this->initialize();
+		}
+
+		if (is_string($str) || ( is_object($str) && method_exists($str, '__toString')))
+		{
+			return pg_escape_literal($this->connID, $str);
+		}
+		elseif (is_bool($str))
+		{
+			return $str ? 'TRUE' : 'FALSE';
+		}
+
+		return parent::escape($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform-dependant string escape
+	 *
+	 * @param  string $str
+	 * @return string
+	 */
+	protected function _escapeString(string $str): string
+	{
+		if (! $this->connID)
+		{
+			$this->initialize();
+		}
+
+		return pg_escape_string($this->connID, $str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates the SQL for listing tables in a platform-dependent manner.
+	 *
+	 * @param boolean $prefixLimit
+	 *
+	 * @return string
+	 */
+	protected function _listTables(bool $prefixLimit = false): string
+	{
+		$sql = 'SELECT "table_name" FROM "information_schema"."tables" WHERE "table_schema" = \'' . $this->schema . "'";
+
+		if ($prefixLimit !== false && $this->DBPrefix !== '')
+		{
+			return $sql . ' AND "table_name" LIKE \''
+					. $this->escapeLikeString($this->DBPrefix) . "%' "
+					. sprintf($this->likeEscapeStr, $this->likeEscapeChar);
+		}
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates a platform-specific query string so that the column names can be fetched.
+	 *
+	 * @param string $table
+	 *
+	 * @return string
+	 */
+	protected function _listColumns(string $table = ''): string
+	{
+		return 'SELECT "column_name"
+			FROM "information_schema"."columns"
+			WHERE LOWER("table_name") = '
+				. $this->escape($this->DBPrefix . strtolower($table));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with field data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _fieldData(string $table): array
+	{
+		$sql = 'SELECT "column_name", "data_type", "character_maximum_length", "numeric_precision", "column_default"
+			FROM "information_schema"."columns"
+			WHERE LOWER("table_name") = '
+				. $this->escape(strtolower($table));
+
+		if (($query = $this->query($sql)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetFieldData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		for ($i = 0, $c = count($query); $i < $c; $i ++)
+		{
+			$retVal[$i]             = new \stdClass();
+			$retVal[$i]->name       = $query[$i]->column_name;
+			$retVal[$i]->type       = $query[$i]->data_type;
+			$retVal[$i]->default    = $query[$i]->column_default;
+			$retVal[$i]->max_length = $query[$i]->character_maximum_length > 0 ? $query[$i]->character_maximum_length : $query[$i]->numeric_precision;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with index data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _indexData(string $table): array
+	{
+		$sql = 'SELECT "indexname", "indexdef"
+			FROM "pg_indexes"
+			WHERE LOWER("tablename") = ' . $this->escape(strtolower($table)) . '
+			AND "schemaname" = ' . $this->escape('public');
+
+		if (($query = $this->query($sql)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetIndexData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		foreach ($query as $row)
+		{
+			$obj         = new \stdClass();
+			$obj->name   = $row->indexname;
+			$_fields     = explode(',', preg_replace('/^.*\((.+?)\)$/', '$1', trim($row->indexdef)));
+			$obj->fields = array_map(function ($v) {
+				return trim($v);
+			}, $_fields);
+
+			if (strpos($row->indexdef, 'CREATE UNIQUE INDEX pk') === 0)
+			{
+				$obj->type = 'PRIMARY';
+			}
+			else
+			{
+				$obj->type = (strpos($row->indexdef, 'CREATE UNIQUE') === 0) ? 'UNIQUE' : 'INDEX';
+			}
+
+			$retVal[$obj->name] = $obj;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with Foreign key data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _foreignKeyData(string $table): array
+	{
+		$sql = 'SELECT
+                            tc.constraint_name, tc.table_name, kcu.column_name,
+                            ccu.table_name AS foreign_table_name,
+                            ccu.column_name AS foreign_column_name
+                        FROM information_schema.table_constraints AS tc
+                        JOIN information_schema.key_column_usage AS kcu
+                            ON tc.constraint_name = kcu.constraint_name
+                        JOIN information_schema.constraint_column_usage AS ccu
+                            ON ccu.constraint_name = tc.constraint_name
+                        WHERE constraint_type = ' . $this->escape('FOREIGN KEY') . ' AND
+                            tc.table_name = ' . $this->escape($table);
+
+		if (($query = $this->query($sql)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetForeignKeyData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		foreach ($query as $row)
+		{
+			$obj                      = new \stdClass();
+			$obj->constraint_name     = $row->constraint_name;
+			$obj->table_name          = $row->table_name;
+			$obj->column_name         = $row->column_name;
+			$obj->foreign_table_name  = $row->foreign_table_name;
+			$obj->foreign_column_name = $row->foreign_column_name;
+			$retVal[]                 = $obj;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to disable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _disableForeignKeyChecks()
+	{
+		return 'SET CONSTRAINTS ALL DEFERRED';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to enable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _enableForeignKeyChecks()
+	{
+		return 'SET CONSTRAINTS ALL IMMEDIATE;';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the last error code and message.
+	 *
+	 * Must return an array with keys 'code' and 'message':
+	 *
+	 *  return ['code' => null, 'message' => null);
+	 *
+	 * @return array
+	 */
+	public function error(): array
+	{
+		return [
+			'code'    => '',
+			'message' => pg_last_error($this->connID),
+		];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Insert ID
+	 *
+	 * @return integer
+	 */
+	public function insertID(): int
+	{
+		$v = pg_version($this->connID);
+		// 'server' key is only available since PostgreSQL 7.4
+		$v = $v['server'] ?? 0;
+
+		$table  = func_num_args() > 0 ? func_get_arg(0) : null;
+		$column = func_num_args() > 1 ? func_get_arg(1) : null;
+
+		if ($table === null && $v >= '8.1')
+		{
+			$sql = 'SELECT LASTVAL() AS ins_id';
+		}
+		elseif ($table !== null)
+		{
+			if ($column !== null && $v >= '8.0')
+			{
+				$sql   = "SELECT pg_get_serial_sequence('{$table}', '{$column}') AS seq";
+				$query = $this->query($sql);
+				$query = $query->getRow();
+				$seq   = $query->seq;
+			}
+			else
+			{
+				// seq_name passed in table parameter
+				$seq = $table;
+			}
+
+			$sql = "SELECT CURRVAL('{$seq}') AS ins_id";
+		}
+		else
+		{
+			return pg_last_oid($this->resultID);
+		}
+
+		$query = $this->query($sql);
+		$query = $query->getRow();
+		return (int) $query->ins_id;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build a DSN from the provided parameters
+	 *
+	 * @return void
+	 */
+	protected function buildDSN()
+	{
+		$this->DSN === '' || $this->DSN = '';
+
+		// If UNIX sockets are used, we shouldn't set a port
+		if (strpos($this->hostname, '/') !== false)
+		{
+			$this->port = '';
+		}
+
+		$this->hostname === '' || $this->DSN = "host={$this->hostname} ";
+
+		if (! empty($this->port) && ctype_digit($this->port))
+		{
+			$this->DSN .= "port={$this->port} ";
+		}
+
+		if ($this->username !== '')
+		{
+			$this->DSN .= "user={$this->username} ";
+
+			// An empty password is valid!
+			// password must be set to null to ignore it.
+
+			$this->password === null || $this->DSN .= "password='{$this->password}' ";
+		}
+
+		$this->database === '' || $this->DSN .= "dbname={$this->database} ";
+
+		// We don't have these options as elements in our standard configuration
+		// array, but they might be set by parse_url() if the configuration was
+		// provided via string> Example:
+		//
+		// postgre://username:password@localhost:5432/database?connect_timeout=5&sslmode=1
+		foreach (['connect_timeout', 'options', 'sslmode', 'service'] as $key)
+		{
+			if (isset($this->{$key}) && is_string($this->{$key}) && $this->{$key} !== '')
+			{
+				$this->DSN .= "{$key}='{$this->{$key}}' ";
+			}
+		}
+
+		$this->DSN = rtrim($this->DSN);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set client encoding
+	 *
+	 * @param  string $charset The client encoding to which the data will be converted.
+	 * @return boolean
+	 */
+	protected function setClientEncoding(string $charset): bool
+	{
+		return pg_set_client_encoding($this->connID, $charset) === 0;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transBegin(): bool
+	{
+		return (bool) pg_query($this->connID, 'BEGIN');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transCommit(): bool
+	{
+		return (bool) pg_query($this->connID, 'COMMIT');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transRollback(): bool
+	{
+		return (bool) pg_query($this->connID, 'ROLLBACK');
+	}
+
+	// --------------------------------------------------------------------
+}

system/Database/Postgre/Forge.php

@@ -0,0 +1,261 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+/**
+ * Forge for Postgre
+ */
+class Forge extends \CodeIgniter\Database\Forge
+{
+
+	/**
+     * CHECK DATABASE EXIST statement
+     *
+     * @var string
+     */
+	protected $checkDatabaseExistStr = 'SELECT 1 FROM pg_database WHERE datname = ?';
+	
+	/**
+	 * DROP CONSTRAINT statement
+	 *
+	 * @var string
+	 */
+	protected $dropConstraintStr = 'ALTER TABLE %s DROP CONSTRAINT %s';
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var array
+	 */
+	protected $_unsigned = [
+		'INT2'     => 'INTEGER',
+		'SMALLINT' => 'INTEGER',
+		'INT'      => 'BIGINT',
+		'INT4'     => 'BIGINT',
+		'INTEGER'  => 'BIGINT',
+		'INT8'     => 'NUMERIC',
+		'BIGINT'   => 'NUMERIC',
+		'REAL'     => 'DOUBLE PRECISION',
+		'FLOAT'    => 'DOUBLE PRECISION',
+	];
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var string
+	 */
+	protected $_null = 'NULL';
+	
+	//--------------------------------------------------------------------
+
+	/**
+	 * CREATE TABLE attributes
+	 *
+	 * @param  array $attributes Associative array of table attributes
+	 * @return string
+	 */
+	protected function _createTableAttributes(array $attributes): string
+	{
+		return '';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param string $alter_type ALTER type
+	 * @param string $table      Table name
+	 * @param mixed  $field      Column definition
+	 *
+	 * @return string|array
+	 */
+	protected function _alterTable(string $alter_type, string $table, $field)
+	{
+		if (in_array($alter_type, ['DROP', 'ADD'], true))
+		{
+			return parent::_alterTable($alter_type, $table, $field);
+		}
+
+		$sql  = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
+		$sqls = [];
+		foreach ($field as $data)
+		{
+			if ($data['_literal'] !== false)
+			{
+				return false;
+			}
+
+			if (version_compare($this->db->getVersion(), '8', '>=') && isset($data['type']))
+			{
+				$sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
+						. " TYPE {$data['type']}{$data['length']}";
+			}
+
+			if (! empty($data['default']))
+			{
+				$sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
+						. " SET DEFAULT {$data['default']}";
+			}
+
+			if (isset($data['null']))
+			{
+				$sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
+						. ($data['null'] === true ? ' DROP' : ' SET') . ' NOT NULL';
+			}
+
+			if (! empty($data['new_name']))
+			{
+				$sqls[] = $sql . ' RENAME COLUMN ' . $this->db->escapeIdentifiers($data['name'])
+						. ' TO ' . $this->db->escapeIdentifiers($data['new_name']);
+			}
+
+			if (! empty($data['comment']))
+			{
+				$sqls[] = 'COMMENT ON COLUMN' . $this->db->escapeIdentifiers($table)
+						. '.' . $this->db->escapeIdentifiers($data['name'])
+						. " IS {$data['comment']}";
+			}
+		}
+
+		return $sqls;
+	}
+
+		//--------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param  array $field
+	 * @return string
+	 */
+	protected function _processColumn(array $field): string
+	{
+		return $this->db->escapeIdentifiers($field['name'])
+				. ' ' . $field['type'] . $field['length']
+				. $field['default']
+				. $field['null']
+				. $field['auto_increment']
+				. $field['unique'];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param array &$attributes
+	 *
+	 * @return void
+	 */
+	protected function _attributeType(array &$attributes)
+	{
+		// Reset field lengths for data types that don't support it
+		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== false)
+		{
+			$attributes['CONSTRAINT'] = null;
+		}
+
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'TINYINT':
+				$attributes['TYPE']     = 'SMALLINT';
+				$attributes['UNSIGNED'] = false;
+				break;
+			case 'MEDIUMINT':
+				$attributes['TYPE']     = 'INTEGER';
+				$attributes['UNSIGNED'] = false;
+				break;
+			case 'DATETIME':
+				$attributes['TYPE'] = 'TIMESTAMP';
+				break;
+			default:
+				break;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param array &$attributes
+	 * @param array &$field
+	 *
+	 * @return void
+	 */
+	protected function _attributeAutoIncrement(array &$attributes, array &$field)
+	{
+		if (! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true)
+		{
+			$field['type'] = $field['type'] === 'NUMERIC' ? 'BIGSERIAL' : 'SERIAL';
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Drop Table
+	 *
+	 * Generates a platform-specific DROP TABLE string
+	 *
+	 * @param string  $table     Table name
+	 * @param boolean $if_exists Whether to add an IF EXISTS condition
+	 * @param boolean $cascade
+	 *
+	 * @return string
+	 */
+	protected function _dropTable(string $table, bool $if_exists, bool $cascade): string
+	{
+		$sql = parent::_dropTable($table, $if_exists, $cascade);
+
+		if ($cascade === true)
+		{
+			$sql .= ' CASCADE';
+		}
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+}

system/Database/Postgre/PreparedQuery.php

@@ -0,0 +1,160 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+use CodeIgniter\Database\PreparedQueryInterface;
+use CodeIgniter\Database\BasePreparedQuery;
+
+/**
+ * Prepared query for Postgre
+ */
+class PreparedQuery extends BasePreparedQuery implements PreparedQueryInterface
+{
+
+	/**
+	 * Stores the name this query can be
+	 * used under by postgres. Only used internally.
+	 *
+	 * @var string
+	 */
+	protected $name;
+
+	/**
+	 * The result resource from a successful
+	 * pg_exec. Or false.
+	 *
+	 * @var
+	 */
+	protected $result;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares the query against the database, and saves the connection
+	 * info necessary to execute the query later.
+	 *
+	 * NOTE: This version is based on SQL code. Child classes should
+	 * override this method.
+	 *
+	 * @param string $sql
+	 * @param array  $options Passed to the connection's prepare statement.
+	 *                        Unused in the MySQLi driver.
+	 *
+	 * @return mixed
+	 * @throws \Exception
+	 */
+	public function _prepare(string $sql, array $options = [])
+	{
+		$this->name = random_int(1, 10000000000000000);
+
+		$sql = $this->parameterize($sql);
+
+		// Update the query object since the parameters are slightly different
+		// than what was put in.
+		$this->query->setQuery($sql);
+
+		if (! $this->statement = pg_prepare($this->db->connID, $this->name, $sql))
+		{
+			$this->errorCode   = 0;
+			$this->errorString = pg_last_error($this->db->connID);
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Takes a new set of data and runs it against the currently
+	 * prepared query. Upon success, will return a Results object.
+	 *
+	 * @param array $data
+	 *
+	 * @return boolean
+	 */
+	public function _execute(array $data): bool
+	{
+		if (is_null($this->statement))
+		{
+			throw new \BadMethodCallException('You must call prepare before trying to execute a prepared statement.');
+		}
+
+		$this->result = pg_execute($this->db->connID, $this->name, $data);
+
+		return (bool) $this->result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result object for the prepared query.
+	 *
+	 * @return mixed
+	 */
+	public function _getResult()
+	{
+		return $this->result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Replaces the ? placeholders with $1, $2, etc parameters for use
+	 * within the prepared query.
+	 *
+	 * @param string $sql
+	 *
+	 * @return string
+	 */
+	public function parameterize(string $sql): string
+	{
+		// Track our current value
+		$count = 0;
+
+		$sql = preg_replace_callback('/\?/', function ($matches) use (&$count) {
+			$count ++;
+			return "\${$count}";
+		}, $sql);
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Postgre/Result.php

@@ -0,0 +1,171 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+use CodeIgniter\Database\BaseResult;
+use CodeIgniter\Database\ResultInterface;
+use CodeIgniter\Entity;
+
+/**
+ * Result for Postgre
+ */
+class Result extends BaseResult implements ResultInterface
+{
+
+	/**
+	 * Gets the number of fields in the result set.
+	 *
+	 * @return integer
+	 */
+	public function getFieldCount(): int
+	{
+		return pg_num_fields($this->resultID);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of column names in the result set.
+	 *
+	 * @return array
+	 */
+	public function getFieldNames(): array
+	{
+		$fieldNames = [];
+		for ($i = 0, $c = $this->getFieldCount(); $i < $c; $i ++)
+		{
+			$fieldNames[] = pg_field_name($this->resultID, $i);
+		}
+
+		return $fieldNames;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of objects representing field meta-data.
+	 *
+	 * @return array
+	 */
+	public function getFieldData(): array
+	{
+		$retVal = [];
+
+		for ($i = 0, $c = $this->getFieldCount(); $i < $c; $i ++)
+		{
+			$retVal[$i]             = new \stdClass();
+			$retVal[$i]->name       = pg_field_name($this->resultID, $i);
+			$retVal[$i]->type       = pg_field_type($this->resultID, $i);
+			$retVal[$i]->max_length = pg_field_size($this->resultID, $i);
+			// $retVal[$i]->primary_key = (int)($fieldData[$i]->flags & 2);
+			// $retVal[$i]->default     = $fieldData[$i]->def;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Frees the current result.
+	 *
+	 * @return void
+	 */
+	public function freeResult()
+	{
+		if (is_resource($this->resultID))
+		{
+			pg_free_result($this->resultID);
+			$this->resultID = false;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Moves the internal pointer to the desired offset. This is called
+	 * internally before fetching results to make sure the result set
+	 * starts at zero.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function dataSeek(int $n = 0)
+	{
+		return pg_result_seek($this->resultID, $n);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an array.
+	 *
+	 * Overridden by driver classes.
+	 *
+	 * @return mixed
+	 */
+	protected function fetchAssoc()
+	{
+		return pg_fetch_assoc($this->resultID);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an object.
+	 *
+	 * Overridden by child classes.
+	 *
+	 * @param string $className
+	 *
+	 * @return object|boolean|Entity
+	 */
+	protected function fetchObject(string $className = 'stdClass')
+	{
+		if (is_subclass_of($className, Entity::class))
+		{
+			return empty($data = $this->fetchAssoc()) ? false : (new $className())->setAttributes($data);
+		}
+		return pg_fetch_object($this->resultID, null, $className);
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Postgre/Utils.php

@@ -0,0 +1,79 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\Postgre;
+
+use CodeIgniter\Database\BaseUtils;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Utils for Postgre
+ */
+class Utils extends BaseUtils
+{
+
+	/**
+	 * List databases statement
+	 *
+	 * @var string
+	 */
+	protected $listDatabases = 'SELECT datname FROM pg_database';
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var string
+	 */
+	protected $optimizeTable = 'REINDEX TABLE %s';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform dependent version of the backup function.
+	 *
+	 * @param array|null $prefs
+	 *
+	 * @return mixed
+	 */
+	public function _backup(array $prefs = null)
+	{
+		throw new DatabaseException('Unsupported feature of the database platform you are using.');
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/PreparedQueryInterface.php

@@ -0,0 +1,106 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Prepared query interface
+ */
+interface PreparedQueryInterface
+{
+
+	/**
+	 * Takes a new set of data and runs it against the currently
+	 * prepared query. Upon success, will return a Results object.
+	 *
+	 * @param array $data
+	 *
+	 * @return ResultInterface
+	 */
+	public function execute(...$data);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares the query against the database, and saves the connection
+	 * info necessary to execute the query later.
+	 *
+	 * @param string $sql
+	 * @param array  $options Passed to the connection's prepare statement.
+	 *
+	 * @return mixed
+	 */
+	public function prepare(string $sql, array $options = []);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Explicity closes the statement.
+	 */
+	public function close();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the SQL that has been prepared.
+	 *
+	 * @return string
+	 */
+	public function getQueryString(): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error code created while executing this statement.
+	 *
+	 * @return integer
+	 */
+	public function getErrorCode(): int;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error message created while executing this statement.
+	 *
+	 * @return string
+	 */
+	public function getErrorMessage(): string;
+
+	//--------------------------------------------------------------------
+}

system/Database/Query.php

@@ -0,0 +1,506 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Query builder
+ *
+ * @package CodeIgniter\Database
+ */
+class Query implements QueryInterface
+{
+
+	/**
+	 * The query string, as provided by the user.
+	 *
+	 * @var string
+	 */
+	protected $originalQueryString;
+
+	/**
+	 * The final query string after binding, etc.
+	 *
+	 * @var string
+	 */
+	protected $finalQueryString;
+
+	/**
+	 * The binds and their values used for binding.
+	 *
+	 * @var array
+	 */
+	protected $binds = [];
+
+	/**
+	 * Bind marker
+	 *
+	 * Character used to identify values in a prepared statement.
+	 *
+	 * @var string
+	 */
+	protected $bindMarker = '?';
+
+	/**
+	 * The start time in seconds with microseconds
+	 * for when this query was executed.
+	 *
+	 * @var float
+	 */
+	protected $startTime;
+
+	/**
+	 * The end time in seconds with microseconds
+	 * for when this query was executed.
+	 *
+	 * @var float
+	 */
+	protected $endTime;
+
+	/**
+	 * The error code, if any.
+	 *
+	 * @var integer
+	 */
+	protected $errorCode;
+
+	/**
+	 * The error message, if any.
+	 *
+	 * @var string
+	 */
+	protected $errorString;
+
+	/**
+	 * Pointer to database connection.
+	 * Mainly for escaping features.
+	 *
+	 * @var BaseConnection
+	 */
+	public $db;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * BaseQuery constructor.
+	 *
+	 * @param $db ConnectionInterface
+	 */
+	public function __construct(&$db)
+	{
+		$this->db = $db;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Sets the raw query string to use for this statement.
+	 *
+	 * @param string  $sql
+	 * @param mixed   $binds
+	 * @param boolean $setEscape
+	 *
+	 * @return $this
+	 */
+	public function setQuery(string $sql, $binds = null, bool $setEscape = true)
+	{
+		$this->originalQueryString = $sql;
+
+		if (! is_null($binds))
+		{
+			if (! is_array($binds))
+			{
+				$binds = [$binds];
+			}
+
+			if ($setEscape)
+			{
+				array_walk($binds, function (&$item) {
+					$item = [
+						$item,
+						true,
+					];
+				});
+			}
+			$this->binds = $binds;
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Will store the variables to bind into the query later.
+	 *
+	 * @param array $binds
+	 *
+	 * @return $this
+	 */
+	public function setBinds(array $binds)
+	{
+		$this->binds = $binds;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the final, processed query string after binding, etal
+	 * has been performed.
+	 *
+	 * @return string
+	 */
+	public function getQuery(): string
+	{
+		if (empty($this->finalQueryString))
+		{
+			$this->finalQueryString = $this->originalQueryString;
+		}
+
+		$this->compileBinds();
+
+		return $this->finalQueryString;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Records the execution time of the statement using microtime(true)
+	 * for it's start and end values. If no end value is present, will
+	 * use the current time to determine total duration.
+	 *
+	 * @param float $start
+	 * @param float $end
+	 *
+	 * @return $this
+	 */
+	public function setDuration(float $start, float $end = null)
+	{
+		$this->startTime = $start;
+
+		if (is_null($end))
+		{
+			$end = microtime(true);
+		}
+
+		$this->endTime = $end;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the start time in seconds with microseconds.
+	 *
+	 * @param boolean $returnRaw
+	 * @param integer $decimals
+	 *
+	 * @return string
+	 */
+	public function getStartTime(bool $returnRaw = false, int $decimals = 6): string
+	{
+		if ($returnRaw)
+		{
+			return $this->startTime;
+		}
+
+		return number_format($this->startTime, $decimals);
+	}
+
+	//--------------------------------------------------------------------
+	/**
+	 * Returns the duration of this query during execution, or null if
+	 * the query has not been executed yet.
+	 *
+	 * @param integer $decimals The accuracy of the returned time.
+	 *
+	 * @return string
+	 */
+	public function getDuration(int $decimals = 6): string
+	{
+		return number_format(($this->endTime - $this->startTime), $decimals);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Stores the error description that happened for this query.
+	 *
+	 * @param integer $code
+	 * @param string  $error
+	 *
+	 * @return $this
+	 */
+	public function setError(int $code, string $error)
+	{
+		$this->errorCode   = $code;
+		$this->errorString = $error;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Reports whether this statement created an error not.
+	 *
+	 * @return boolean
+	 */
+	public function hasError(): bool
+	{
+		return ! empty($this->errorString);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error code created while executing this statement.
+	 *
+	 * @return integer
+	 */
+	public function getErrorCode(): int
+	{
+		return $this->errorCode;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error message created while executing this statement.
+	 *
+	 * @return string
+	 */
+	public function getErrorMessage(): string
+	{
+		return $this->errorString;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Determines if the statement is a write-type query or not.
+	 *
+	 * @return boolean
+	 */
+	public function isWriteType(): bool
+	{
+		return (bool) preg_match(
+						'/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i', $this->originalQueryString);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Swaps out one table prefix for a new one.
+	 *
+	 * @param string $orig
+	 * @param string $swap
+	 *
+	 * @return $this
+	 */
+	public function swapPrefix(string $orig, string $swap)
+	{
+		$sql = empty($this->finalQueryString) ? $this->originalQueryString : $this->finalQueryString;
+
+		$this->finalQueryString = preg_replace('/(\W)' . $orig . '(\S+?)/', '\\1' . $swap . '\\2', $sql);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the original SQL that was passed into the system.
+	 *
+	 * @return string
+	 */
+	public function getOriginalQuery(): string
+	{
+		return $this->originalQueryString;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Escapes and inserts any binds into the finalQueryString object.
+	 *
+	 * @return null|void
+	 */
+	protected function compileBinds()
+	{
+		$sql = $this->finalQueryString;
+
+		$hasNamedBinds = strpos($sql, ':') !== false;
+
+		if (empty($this->binds) || empty($this->bindMarker) ||
+				(strpos($sql, $this->bindMarker) === false &&
+				$hasNamedBinds === false)
+		)
+		{
+			return;
+		}
+
+		if (! is_array($this->binds))
+		{
+			$binds     = [$this->binds];
+			$bindCount = 1;
+		}
+		else
+		{
+			$binds     = $this->binds;
+			$bindCount = count($binds);
+		}
+
+		// Reverse the binds so that duplicate named binds
+		// will be processed prior to the original binds.
+		if (! is_numeric(key(array_slice($binds, 0, 1))))
+		{
+			$binds = array_reverse($binds);
+		}
+
+		// We'll need marker length later
+		$ml = strlen($this->bindMarker);
+
+		if ($hasNamedBinds)
+		{
+			$sql = $this->matchNamedBinds($sql, $binds);
+		}
+		else
+		{
+			$sql = $this->matchSimpleBinds($sql, $binds, $bindCount, $ml);
+		}
+
+		$this->finalQueryString = $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Match bindings
+	 *
+	 * @param  string $sql
+	 * @param  array  $binds
+	 * @return string
+	 */
+	protected function matchNamedBinds(string $sql, array $binds): string
+	{
+		$replacers = [];
+
+		foreach ($binds as $placeholder => $value)
+		{
+			// $value[1] contains the boolean whether should be escaped or not
+			$escapedValue = $value[1] ? $this->db->escape($value[0]) : $value[0];
+
+			// In order to correctly handle backlashes in saved strings
+			// we will need to preg_quote, so remove the wrapping escape characters
+			// otherwise it will get escaped.
+			if (is_array($value[0]))
+			{
+				$escapedValue = '(' . implode(',', $escapedValue) . ')';
+			}
+
+			$replacers[":{$placeholder}:"] = $escapedValue;
+		}
+
+		$sql = strtr($sql, $replacers);
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Match bindings
+	 *
+	 * @param  string  $sql
+	 * @param  array   $binds
+	 * @param  integer $bindCount
+	 * @param  integer $ml
+	 * @return string
+	 */
+	protected function matchSimpleBinds(string $sql, array $binds, int $bindCount, int $ml): string
+	{
+		// Make sure not to replace a chunk inside a string that happens to match the bind marker
+		if ($c = preg_match_all("/'[^']*'/i", $sql, $matches))
+		{
+			$c = preg_match_all('/' . preg_quote($this->bindMarker, '/') . '/i', str_replace($matches[0], str_replace($this->bindMarker, str_repeat(' ', $ml), $matches[0]), $sql, $c), $matches, PREG_OFFSET_CAPTURE);
+
+			// Bind values' count must match the count of markers in the query
+			if ($bindCount !== $c)
+			{
+				return $sql;
+			}
+		}
+		// Number of binds must match bindMarkers in the string.
+		else if (($c = preg_match_all('/' . preg_quote($this->bindMarker, '/') . '/i', $sql, $matches, PREG_OFFSET_CAPTURE)) !== $bindCount)
+		{
+			return $sql;
+		}
+
+		do
+		{
+			$c--;
+			$escapedValue = $binds[$c][1] ? $this->db->escape($binds[$c][0]) : $binds[$c][0];
+			if (is_array($escapedValue))
+			{
+				$escapedValue = '(' . implode(',', $escapedValue) . ')';
+			}
+			$sql = substr_replace($sql, $escapedValue, $matches[0][$c][1], $ml);
+		}
+		while ($c !== 0);
+
+		return $sql;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Return text representation of the query
+	 *
+	 * @return string
+	 */
+	public function __toString(): string
+	{
+		return $this->getQuery();
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/QueryInterface.php

@@ -0,0 +1,159 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Interface QueryInterface
+ *
+ * Represents a single statement that can be executed against the database.
+ * Statements are platform-specific and can handle binding of binds.
+ *
+ * @package CodeIgniter\Database
+ */
+interface QueryInterface
+{
+
+	/**
+	 * Sets the raw query string to use for this statement.
+	 *
+	 * @param string  $sql
+	 * @param mixed   $binds
+	 * @param boolean $setEscape
+	 *
+	 * @return mixed
+	 */
+	public function setQuery(string $sql, $binds = null, bool $setEscape = true);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the final, processed query string after binding, etal
+	 * has been performed.
+	 *
+	 * @return mixed
+	 */
+	public function getQuery();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Records the execution time of the statement using microtime(true)
+	 * for it's start and end values. If no end value is present, will
+	 * use the current time to determine total duration.
+	 *
+	 * @param float $start
+	 * @param float $end
+	 *
+	 * @return mixed
+	 */
+	public function setDuration(float $start, float $end = null);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the duration of this query during execution, or null if
+	 * the query has not been executed yet.
+	 *
+	 * @param integer $decimals The accuracy of the returned time.
+	 *
+	 * @return string
+	 */
+	public function getDuration(int $decimals = 6): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Stores the error description that happened for this query.
+	 *
+	 * @param integer $code
+	 * @param string  $error
+	 */
+	public function setError(int $code, string $error);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Reports whether this statement created an error not.
+	 *
+	 * @return boolean
+	 */
+	public function hasError(): bool;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error code created while executing this statement.
+	 *
+	 * @return integer
+	 */
+	public function getErrorCode(): int;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the error message created while executing this statement.
+	 *
+	 * @return string
+	 */
+	public function getErrorMessage(): string;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Determines if the statement is a write-type query or not.
+	 *
+	 * @return boolean
+	 */
+	public function isWriteType(): bool;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Swaps out one table prefix for a new one.
+	 *
+	 * @param string $orig
+	 * @param string $swap
+	 *
+	 * @return mixed
+	 */
+	public function swapPrefix(string $orig, string $swap);
+
+	//--------------------------------------------------------------------
+}

system/Database/ResultInterface.php

@@ -0,0 +1,264 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+/**
+ * Interface ResultInterface
+ */
+interface ResultInterface
+{
+
+	/**
+	 * Retrieve the results of the query. Typically an array of
+	 * individual data rows, which can be either an 'array', an
+	 * 'object', or a custom class name.
+	 *
+	 * @param string $type The row type. Either 'array', 'object', or a class name to use
+	 *
+	 * @return mixed
+	 */
+	public function getResult(string $type = 'object'): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of custom objects.
+	 *
+	 * @param string $className The name of the class to use.
+	 *
+	 * @return mixed
+	 */
+	public function getCustomResultObject(string $className);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of arrays.
+	 *
+	 * If no results, an empty array is returned.
+	 *
+	 * @return array
+	 */
+	public function getResultArray(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the results as an array of objects.
+	 *
+	 * If no results, an empty array is returned.
+	 *
+	 * @return array
+	 */
+	public function getResultObject(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Wrapper object to return a row as either an array, an object, or
+	 * a custom class.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param mixed  $n    The index of the results to return
+	 * @param string $type The type of result object. 'array', 'object' or class name.
+	 *
+	 * @return mixed
+	 */
+	public function getRow($n = 0, string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a row as a custom class instance.
+	 *
+	 * If row doesn't exists, returns null.
+	 *
+	 * @param integer $n
+	 * @param string  $className
+	 *
+	 * @return mixed
+	 */
+	public function getCustomRowObject(int $n, string $className);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a single row from the results as an array.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function getRowArray(int $n = 0);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a single row from the results as an object.
+	 *
+	 * If row doesn't exist, returns null.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function getRowObject(int $n = 0);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Assigns an item into a particular column slot.
+	 *
+	 * @param $key
+	 * @param null $value
+	 *
+	 * @return mixed
+	 */
+	public function setRow($key, $value = null);
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "first" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getFirstRow(string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "last" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getLastRow(string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "next" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getNextRow(string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the "previous" row of the current results.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getPreviousRow(string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an unbuffered row and move the pointer to the next row.
+	 *
+	 * @param string $type
+	 *
+	 * @return mixed
+	 */
+	public function getUnbufferedRow(string $type = 'object');
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Gets the number of fields in the result set.
+	 *
+	 * @return integer
+	 */
+	public function getFieldCount(): int;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of column names in the result set.
+	 *
+	 * @return array
+	 */
+	public function getFieldNames(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of objects representing field meta-data.
+	 *
+	 * @return array
+	 */
+	public function getFieldData(): array;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Frees the current result.
+	 *
+	 * @return void
+	 */
+	public function freeResult();
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Moves the internal pointer to the desired offset. This is called
+	 * internally before fetching results to make sure the result set
+	 * starts at zero.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 */
+	public function dataSeek(int $n = 0);
+
+	//--------------------------------------------------------------------
+}

system/Database/SQLite3/Builder.php

@@ -0,0 +1,111 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\BaseBuilder;
+
+/**
+ * Builder for SQLite3
+ */
+class Builder extends BaseBuilder
+{
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var string
+	 */
+	protected $escapeChar = '`';
+
+	/**
+	 * Default installs of SQLite typically do not
+	 * support limiting delete clauses.
+	 *
+	 * @var boolean
+	 */
+	protected $canLimitDeletes = false;
+
+	/**
+	 * Default installs of SQLite do no support
+	 * limiting update queries in combo with WHERE.
+	 *
+	 * @var boolean
+	 */
+	protected $canLimitWhereUpdates = false;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Replace statement
+	 *
+	 * Generates a platform-specific replace string from the supplied data
+	 *
+	 * @param string $table  the table name
+	 * @param array  $keys   the insert keys
+	 * @param array  $values the insert values
+	 *
+	 * @return string
+	 */
+	protected function _replace(string $table, array $keys, array $values): string
+	{
+		return 'INSERT OR ' . parent::_replace($table, $keys, $values);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Truncate statement
+	 *
+	 * Generates a platform-specific truncate string from the supplied data
+	 *
+	 * If the database does not support the TRUNCATE statement,
+	 * then this method maps to 'DELETE FROM table'
+	 *
+	 * @param  string $table
+	 * @return string
+	 */
+	protected function _truncate(string $table): string
+	{
+		return 'DELETE FROM ' . $table;
+	}
+
+	//--------------------------------------------------------------------
+
+}

system/Database/SQLite3/Connection.php

@@ -0,0 +1,542 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\BaseConnection;
+use CodeIgniter\Database\ConnectionInterface;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Connection for SQLite3
+ */
+class Connection extends BaseConnection implements ConnectionInterface
+{
+
+	/**
+	 * Database driver
+	 *
+	 * @var string
+	 */
+	public $DBDriver = 'SQLite3';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var array
+	 */
+	protected $_random_keyword = [
+		'RANDOM()',
+	];
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Connect to the database.
+	 *
+	 * @param boolean $persistent
+	 *
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function connect(bool $persistent = false)
+	{
+		if ($persistent && $this->db->DBDebug)
+		{
+			throw new DatabaseException('SQLite3 doesn\'t support persistent connections.');
+		}
+		try
+		{
+			return (! $this->password)
+				? new \SQLite3($this->database)
+				: new \SQLite3($this->database, SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE, $this->password);
+		}
+		catch (\Exception $e)
+		{
+			throw new DatabaseException('SQLite3 error: ' . $e->getMessage());
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Keep or establish the connection if no queries have been sent for
+	 * a length of time exceeding the server's idle timeout.
+	 *
+	 * @return void
+	 */
+	public function reconnect()
+	{
+		$this->close();
+		$this->initialize();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Close the database connection.
+	 *
+	 * @return void
+	 */
+	protected function _close()
+	{
+		$this->connID->close();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Select a specific database table to use.
+	 *
+	 * @param string $databaseName
+	 *
+	 * @return boolean
+	 */
+	public function setDatabase(string $databaseName): bool
+	{
+		return false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns a string containing the version of the database being used.
+	 *
+	 * @return string
+	 */
+	public function getVersion(): string
+	{
+		if (isset($this->dataCache['version']))
+		{
+			return $this->dataCache['version'];
+		}
+
+		$version = \SQLite3::version();
+
+		return $this->dataCache['version'] = $version['versionString'];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Execute the query
+	 *
+	 * @param string $sql
+	 *
+	 * @return mixed    \SQLite3Result object or bool
+	 */
+	public function execute(string $sql)
+	{
+		return $this->isWriteType($sql)
+			? $this->connID->exec($sql)
+			: $this->connID->query($sql);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the total number of rows affected by this query.
+	 *
+	 * @return integer
+	 */
+	public function affectedRows(): int
+	{
+		return $this->connID->changes();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform-dependant string escape
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function _escapeString(string $str): string
+	{
+		return $this->connID->escapeString($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates the SQL for listing tables in a platform-dependent manner.
+	 *
+	 * @param boolean $prefixLimit
+	 *
+	 * @return string
+	 */
+	protected function _listTables(bool $prefixLimit = false): string
+	{
+		return 'SELECT "NAME" FROM "SQLITE_MASTER" WHERE "TYPE" = \'table\''
+			   . ' AND "NAME" NOT LIKE \'sqlite!_%\' ESCAPE \'!\''
+			   . (($prefixLimit !== false && $this->DBPrefix !== '')
+				? ' AND "NAME" LIKE \'' . $this->escapeLikeString($this->DBPrefix) . '%\' ' . sprintf($this->likeEscapeStr,
+					$this->likeEscapeChar)
+				: '');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates a platform-specific query string so that the column names can be fetched.
+	 *
+	 * @param string $table
+	 *
+	 * @return string
+	 */
+	protected function _listColumns(string $table = ''): string
+	{
+		return 'PRAGMA TABLE_INFO(' . $this->protectIdentifiers($table, true, null, false) . ')';
+	}
+
+	/**
+	 * Fetch Field Names
+	 *
+	 * @param string $table Table name
+	 *
+	 * @return array|false
+	 * @throws DatabaseException
+	 */
+	public function getFieldNames(string $table)
+	{
+		// Is there a cached result?
+		if (isset($this->dataCache['field_names'][$table]))
+		{
+			return $this->dataCache['field_names'][$table];
+		}
+
+		if (empty($this->connID))
+		{
+			$this->initialize();
+		}
+
+		if (false === ($sql = $this->_listColumns($table)))
+		{
+			if ($this->DBDebug)
+			{
+				throw new DatabaseException(lang('Database.featureUnavailable'));
+			}
+
+			return false;
+		}
+
+		$query                                  = $this->query($sql);
+		$this->dataCache['field_names'][$table] = [];
+
+		foreach ($query->getResultArray() as $row)
+		{
+			// Do we know from where to get the column's name?
+			if (! isset($key))
+			{
+				if (isset($row['column_name']))
+				{
+					$key = 'column_name';
+				}
+				elseif (isset($row['COLUMN_NAME']))
+				{
+					$key = 'COLUMN_NAME';
+				}
+				elseif (isset($row['name']))
+				{
+					$key = 'name';
+				}
+				else
+				{
+					// We have no other choice but to just get the first element's key.
+					$key = key($row);
+				}
+			}
+
+			$this->dataCache['field_names'][$table][] = $row[$key];
+		}
+
+		return $this->dataCache['field_names'][$table];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with field data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _fieldData(string $table): array
+	{
+		if (($query = $this->query('PRAGMA TABLE_INFO(' . $this->protectIdentifiers($table, true, null,
+					false) . ')')) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetFieldData'));
+		}
+		$query = $query->getResultObject();
+
+		if (empty($query))
+		{
+			return [];
+		}
+		$retVal = [];
+		for ($i = 0, $c = count($query); $i < $c; $i++)
+		{
+			$retVal[$i]              = new \stdClass();
+			$retVal[$i]->name        = $query[$i]->name;
+			$retVal[$i]->type        = $query[$i]->type;
+			$retVal[$i]->max_length  = null;
+			$retVal[$i]->default     = $query[$i]->dflt_value;
+			$retVal[$i]->primary_key = isset($query[$i]->pk) ? (bool)$query[$i]->pk : false;
+			$retVal[$i]->nullable    = isset($query[$i]->notnull) ? ! (bool)$query[$i]->notnull : false;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with index data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 * @throws DatabaseException
+	 */
+	public function _indexData(string $table): array
+	{
+		// Get indexes
+		// Don't use PRAGMA index_list, so we can preserve index order
+		$sql = "SELECT name FROM sqlite_master WHERE type='index' AND tbl_name=" . $this->escape(strtolower($table));
+		if (($query = $this->query($sql)) === false)
+		{
+			throw new DatabaseException(lang('Database.failGetIndexData'));
+		}
+		$query = $query->getResultObject();
+
+		$retVal = [];
+		foreach ($query as $row)
+		{
+			$obj       = new \stdClass();
+			$obj->name = $row->name;
+
+			// Get fields for index
+			$obj->fields = [];
+			if (($fields = $this->query('PRAGMA index_info(' . $this->escape(strtolower($row->name)) . ')')) === false)
+			{
+				throw new DatabaseException(lang('Database.failGetIndexData'));
+			}
+			$fields = $fields->getResultObject();
+
+			foreach ($fields as $field)
+			{
+				$obj->fields[] = $field->name;
+			}
+
+			$retVal[$obj->name] = $obj;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns an array of objects with Foreign key data
+	 *
+	 * @param  string $table
+	 * @return \stdClass[]
+	 */
+	public function _foreignKeyData(string $table): array
+	{
+		if ($this->supportsForeignKeys() !== true)
+		{
+			return [];
+		}
+
+		$tables = $this->listTables();
+
+		if (empty($tables))
+		{
+			return [];
+		}
+
+		$retVal = [];
+
+		foreach ($tables as $table)
+		{
+			$query = $this->query("PRAGMA foreign_key_list({$table})")->getResult();
+
+			foreach ($query as $row)
+			{
+				$obj                     = new \stdClass();
+				$obj->constraint_name    = $row->from . ' to ' . $row->table . '.' . $row->to;
+				$obj->table_name         = $table;
+				$obj->foreign_table_name = $row->table;
+				$obj->sequence           = $row->seq;
+
+				$retVal[] = $obj;
+			}
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to disable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _disableForeignKeyChecks()
+	{
+		return 'PRAGMA foreign_keys = OFF';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns platform-specific SQL to enable foreign key checks.
+	 *
+	 * @return string
+	 */
+	protected function _enableForeignKeyChecks()
+	{
+		return 'PRAGMA foreign_keys = ON';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the last error code and message.
+	 *
+	 * Must return an array with keys 'code' and 'message':
+	 *
+	 *  return ['code' => null, 'message' => null);
+	 *
+	 * @return array
+	 */
+	public function error(): array
+	{
+		return [
+			'code'    => $this->connID->lastErrorCode(),
+			'message' => $this->connID->lastErrorMsg(),
+		];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Insert ID
+	 *
+	 * @return integer
+	 */
+	public function insertID(): int
+	{
+		return $this->connID->lastInsertRowID();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transBegin(): bool
+	{
+		return $this->connID->exec('BEGIN TRANSACTION');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transCommit(): bool
+	{
+		return $this->connID->exec('END TRANSACTION');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return boolean
+	 */
+	protected function _transRollback(): bool
+	{
+		return $this->connID->exec('ROLLBACK');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Determines if the statement is a write-type query or not.
+	 *
+	 * @return boolean
+	 */
+	public function isWriteType($sql): bool
+	{
+		return (bool)preg_match(
+			'/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i',
+			$sql);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Checks to see if the current install supports Foreign Keys
+	 * and has them enabled.
+	 *
+	 * @return boolean
+	 */
+	public function supportsForeignKeys(): bool
+	{
+		$result = $this->simpleQuery('PRAGMA foreign_keys');
+
+		return (bool)$result;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/SQLite3/Forge.php

@@ -0,0 +1,333 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\ConnectionInterface;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Forge for SQLite3
+ */
+class Forge extends \CodeIgniter\Database\Forge
+{
+
+	/**
+	 * UNSIGNED support
+	 *
+	 * @var boolean|array
+	 */
+	protected $_unsigned = false;
+
+	/**
+	 * NULL value representation in CREATE/ALTER TABLE statements
+	 *
+	 * @var string
+	 */
+	protected $_null = 'NULL';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor.
+	 *
+	 * @param $db ConnectionInterface
+	 */
+	public function __construct(ConnectionInterface $db)
+	{
+		parent::__construct($db);
+
+		if (version_compare($this->db->getVersion(), '3.3', '<'))
+		{
+			$this->createTableIfStr = false;
+			$this->dropTableIfStr   = false;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Create database
+	 *
+	 * @param string $dbName
+	 * @param boolean $ifNotExists Whether to add IF NOT EXISTS condition
+	 *
+	 * @return boolean
+	 */
+	public function createDatabase(string $dbName, bool $ifNotExists = false): bool
+	{
+		// In SQLite, a database is created when you connect to the database.
+		// We'll return TRUE so that an error isn't generated.
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Drop database
+	 *
+	 * @param string $dbName
+	 *
+	 * @return boolean
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function dropDatabase(string $dbName): bool
+	{
+		// In SQLite, a database is dropped when we delete a file
+		if (! is_file($dbName))
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unable to drop the specified database.');
+			}
+
+			return false;
+		}
+
+		// We need to close the pseudo-connection first
+		$this->db->close();
+		if (! @unlink($dbName))
+		{
+			if ($this->db->DBDebug)
+			{
+				throw new DatabaseException('Unable to drop the specified database.');
+			}
+
+			return false;
+		}
+
+		if (! empty($this->db->dataCache['db_names']))
+		{
+			$key = array_search(strtolower($dbName), array_map('strtolower', $this->db->dataCache['db_names']), true);
+			if ($key !== false)
+			{
+				unset($this->db->dataCache['db_names'][$key]);
+			}
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * ALTER TABLE
+	 *
+	 * @param string $alter_type ALTER type
+	 * @param string $table      Table name
+	 * @param mixed  $field      Column definition
+	 *
+	 * @return string|array
+	 */
+	protected function _alterTable(string $alter_type, string $table, $field)
+	{
+		switch ($alter_type)
+		{
+			case 'DROP':
+				$sqlTable = new Table($this->db, $this);
+
+				$sqlTable->fromTable($table)
+					->dropColumn($field)
+					->run();
+
+				return '';
+				break;
+			case 'CHANGE':
+				$sqlTable = new Table($this->db, $this);
+
+				$sqlTable->fromTable($table)
+						 ->modifyColumn($field)
+						 ->run();
+
+				return null;
+				break;
+			default:
+				return parent::_alterTable($alter_type, $table, $field);
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Process column
+	 *
+	 * @param array $field
+	 *
+	 * @return string
+	 */
+	protected function _processColumn(array $field): string
+	{
+		if ($field['type'] === 'TEXT' && strpos($field['length'], "('") === 0)
+		{
+			$field['type'] .= ' CHECK(' . $this->db->escapeIdentifiers($field['name'])
+				. ' IN ' . $field['length'] . ')';
+		}
+
+		return $this->db->escapeIdentifiers($field['name'])
+			   . ' ' . $field['type']
+			   . $field['auto_increment']
+			   . $field['null']
+			   . $field['unique']
+			   . $field['default'];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Process indexes
+	 *
+	 * @param string $table
+	 *
+	 * @return array
+	 */
+	protected function _processIndexes(string $table): array
+	{
+		$sqls = [];
+
+		for ($i = 0, $c = count($this->keys); $i < $c; $i++)
+		{
+			$this->keys[$i] = (array)$this->keys[$i];
+
+			for ($i2 = 0, $c2 = count($this->keys[$i]); $i2 < $c2; $i2++)
+			{
+				if (! isset($this->fields[$this->keys[$i][$i2]]))
+				{
+					unset($this->keys[$i][$i2]);
+				}
+			}
+			if (count($this->keys[$i]) <= 0)
+			{
+				continue;
+			}
+
+			if (in_array($i, $this->uniqueKeys))
+			{
+				$sqls[] = 'CREATE UNIQUE INDEX ' . $this->db->escapeIdentifiers($table . '_' . implode('_', $this->keys[$i]))
+						  . ' ON ' . $this->db->escapeIdentifiers($table)
+						  . ' (' . implode(', ', $this->db->escapeIdentifiers($this->keys[$i])) . ');';
+				continue;
+			}
+
+			$sqls[] = 'CREATE INDEX ' . $this->db->escapeIdentifiers($table . '_' . implode('_', $this->keys[$i]))
+					  . ' ON ' . $this->db->escapeIdentifiers($table)
+					  . ' (' . implode(', ', $this->db->escapeIdentifiers($this->keys[$i])) . ');';
+		}
+
+		return $sqls;
+	}
+
+	//--------------------------------------------------------------------
+	/**
+	 * Field attribute TYPE
+	 *
+	 * Performs a data type mapping between different databases.
+	 *
+	 * @param array &$attributes
+	 *
+	 * @return void
+	 */
+	protected function _attributeType(array &$attributes)
+	{
+		switch (strtoupper($attributes['TYPE']))
+		{
+			case 'ENUM':
+			case 'SET':
+				$attributes['TYPE'] = 'TEXT';
+				break;
+			default:
+				break;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Field attribute AUTO_INCREMENT
+	 *
+	 * @param array &$attributes
+	 * @param array &$field
+	 *
+	 * @return void
+	 */
+	protected function _attributeAutoIncrement(array &$attributes, array &$field)
+	{
+		if (! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true
+			&& stripos($field['type'], 'int') !== false)
+		{
+			$field['type']           = 'INTEGER PRIMARY KEY';
+			$field['default']        = '';
+			$field['null']           = '';
+			$field['unique']         = '';
+			$field['auto_increment'] = ' AUTOINCREMENT';
+
+			$this->primaryKeys = [];
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Foreign Key Drop
+	 *
+	 * @param string $table       Table name
+	 * @param string $foreignName Foreign name
+	 *
+	 * @return boolean
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function dropForeignKey(string $table, string $foreignName): bool
+	{
+		// If this version of SQLite doesn't support it, we're done here
+		if ($this->db->supportsForeignKeys() !== true)
+		{
+			return true;
+		}
+
+		// Otherwise we have to copy the table and recreate
+		// without the foreign key being involved now
+		$sqlTable = new Table($this->db, $this);
+
+		return $sqlTable->fromTable($this->db->DBPrefix . $table)
+			->dropForeignKey($foreignName)
+			->run();
+	}
+
+	//--------------------------------------------------------------------
+
+}

system/Database/SQLite3/PreparedQuery.php

@@ -0,0 +1,143 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\PreparedQueryInterface;
+use CodeIgniter\Database\BasePreparedQuery;
+
+/**
+ * Prepared query for SQLite3
+ */
+
+class PreparedQuery extends BasePreparedQuery implements PreparedQueryInterface
+{
+
+	/**
+	 * The SQLite3Result resource, or false.
+	 *
+	 * @var
+	 */
+	protected $result;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares the query against the database, and saves the connection
+	 * info necessary to execute the query later.
+	 *
+	 * NOTE: This version is based on SQL code. Child classes should
+	 * override this method.
+	 *
+	 * @param string $sql
+	 * @param array  $options Passed to the connection's prepare statement.
+	 *                        Unused in the MySQLi driver.
+	 *
+	 * @return mixed
+	 */
+	public function _prepare(string $sql, array $options = [])
+	{
+		if (! ($this->statement = $this->db->connID->prepare($sql)))
+		{
+			$this->errorCode   = $this->db->connID->lastErrorCode();
+			$this->errorString = $this->db->connID->lastErrorMsg();
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Takes a new set of data and runs it against the currently
+	 * prepared query. Upon success, will return a Results object.
+	 *
+	 * @todo finalize()
+	 *
+	 * @param array $data
+	 *
+	 * @return boolean
+	 */
+	public function _execute(array $data): bool
+	{
+		if (is_null($this->statement))
+		{
+			throw new \BadMethodCallException('You must call prepare before trying to execute a prepared statement.');
+		}
+
+		foreach ($data as $key => $item)
+		{
+			// Determine the type string
+			if (is_integer($item))
+			{
+				$bindType = SQLITE3_INTEGER;
+			}
+			elseif (is_float($item))
+			{
+				$bindType = SQLITE3_FLOAT;
+			}
+			else
+			{
+				$bindType = SQLITE3_TEXT;
+			}
+
+			// Bind it
+			$this->statement->bindValue($key + 1, $item, $bindType);
+		}
+
+		$this->result = $this->statement->execute();
+
+		return $this->result !== false;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result object for the prepared query.
+	 *
+	 * @return mixed
+	 */
+	public function _getResult()
+	{
+		return $this->result;
+	}
+
+	//--------------------------------------------------------------------
+
+}

system/Database/SQLite3/Result.php

@@ -0,0 +1,205 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\BaseResult;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+use CodeIgniter\Database\ResultInterface;
+use CodeIgniter\Entity;
+
+/**
+ * Result for SQLite3
+ */
+class Result extends BaseResult implements ResultInterface
+{
+
+	/**
+	 * Gets the number of fields in the result set.
+	 *
+	 * @return integer
+	 */
+	public function getFieldCount(): int
+	{
+		return $this->resultID->numColumns();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of column names in the result set.
+	 *
+	 * @return array
+	 */
+	public function getFieldNames(): array
+	{
+		$fieldNames = [];
+		for ($i = 0, $c = $this->getFieldCount(); $i < $c; $i ++)
+		{
+			$fieldNames[] = $this->resultID->columnName($i);
+		}
+
+		return $fieldNames;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Generates an array of objects representing field meta-data.
+	 *
+	 * @return array
+	 */
+	public function getFieldData(): array
+	{
+		static $data_types = [
+			SQLITE3_INTEGER => 'integer',
+			SQLITE3_FLOAT   => 'float',
+			SQLITE3_TEXT    => 'text',
+			SQLITE3_BLOB    => 'blob',
+			SQLITE3_NULL    => 'null',
+		];
+
+		$retVal = [];
+
+		for ($i = 0, $c = $this->getFieldCount(); $i < $c; $i ++)
+		{
+			$retVal[$i]             = new \stdClass();
+			$retVal[$i]->name       = $this->resultID->columnName($i);
+			$type                   = $this->resultID->columnType($i);
+			$retVal[$i]->type       = isset($data_types[$type]) ? $data_types[$type] : $type;
+			$retVal[$i]->max_length = null;
+		}
+
+		return $retVal;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Frees the current result.
+	 *
+	 * @return void
+	 */
+	public function freeResult()
+	{
+		if (is_object($this->resultID))
+		{
+			$this->resultID->finalize();
+			$this->resultID = false;
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Moves the internal pointer to the desired offset. This is called
+	 * internally before fetching results to make sure the result set
+	 * starts at zero.
+	 *
+	 * @param integer $n
+	 *
+	 * @return mixed
+	 * @throws \CodeIgniter\Database\Exceptions\DatabaseException
+	 */
+	public function dataSeek(int $n = 0)
+	{
+		if ($n !== 0)
+		{
+			throw new DatabaseException('SQLite3 doesn\'t support seeking to other offset.');
+		}
+
+		return $this->resultID->reset();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an array.
+	 *
+	 * Overridden by driver classes.
+	 *
+	 * @return mixed
+	 */
+	protected function fetchAssoc()
+	{
+		return $this->resultID->fetchArray(SQLITE3_ASSOC);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Returns the result set as an object.
+	 *
+	 * Overridden by child classes.
+	 *
+	 * @param string $className
+	 *
+	 * @return object|boolean
+	 */
+	protected function fetchObject(string $className = 'stdClass')
+	{
+		// No native support for fetching rows as objects
+		if (($row = $this->fetchAssoc()) === false)
+		{
+			return false;
+		}
+		elseif ($className === 'stdClass')
+		{
+			return (object) $row;
+		}
+
+		$classObj = new $className();
+
+		if (is_subclass_of($className, Entity::class))
+		{
+			return $classObj->setAttributes($row);
+		}
+
+		$classSet = \Closure::bind(function ($key, $value) {
+			$this->$key = $value;
+		}, $classObj, $className
+		);
+		foreach (array_keys($row) as $key)
+		{
+			$classSet($key, $row[$key]);
+		}
+		return $classObj;
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/SQLite3/Table.php

@@ -0,0 +1,426 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\Exceptions\DataException;
+
+/**
+ * Class Table
+ *
+ * Provides missing features for altering tables that are common
+ * in other supported databases, but are missing from SQLite.
+ * These are needed in order to support migrations during testing
+ * when another database is used as the primary engine, but
+ * SQLite in memory databases are used for faster test execution.
+ *
+ * @package CodeIgniter\Database\SQLite3
+ */
+class Table
+{
+	/**
+	 * All of the fields this table represents.
+	 *
+	 * @var array
+	 */
+	protected $fields = [];
+
+	/**
+	 * All of the unique/primary keys in the table.
+	 *
+	 * @var array
+	 */
+	protected $keys = [];
+
+	/**
+	 * All of the foreign keys in the table.
+	 *
+	 * @var array
+	 */
+	protected $foreignKeys = [];
+
+	/**
+	 * The name of the table we're working with.
+	 *
+	 * @var string
+	 */
+	protected $tableName;
+
+	/**
+	 * The name of the table, with database prefix
+	 *
+	 * @var string
+	 */
+	protected $prefixedTableName;
+
+	/**
+	 * Database connection.
+	 *
+	 * @var Connection
+	 */
+	protected $db;
+
+	/**
+	 * Handle to our forge.
+	 *
+	 * @var Forge
+	 */
+	protected $forge;
+
+	/**
+	 * Table constructor.
+	 *
+	 * @param Connection $db
+	 * @param Forge      $forge
+	 */
+	public function __construct(Connection $db, Forge $forge)
+	{
+		$this->db    = $db;
+		$this->forge = $forge;
+	}
+
+	/**
+	 * Reads an existing database table and
+	 * collects all of the information needed to
+	 * recreate this table.
+	 *
+	 * @param string $table
+	 *
+	 * @return \CodeIgniter\Database\SQLite3\Table
+	 */
+	public function fromTable(string $table)
+	{
+		$this->prefixedTableName = $table;
+
+		// Remove the prefix, if any, since it's
+		// already been added by the time we get here...
+		$prefix = $this->db->DBPrefix;
+		if (! empty($prefix))
+		{
+			if (strpos($table, $prefix) === 0)
+			{
+				$table = substr($table, strlen($prefix));
+			}
+		}
+
+		if (! $this->db->tableExists($this->prefixedTableName))
+		{
+			throw DataException::forTableNotFound($this->prefixedTableName);
+		}
+
+		$this->tableName = $table;
+
+		$this->fields = $this->formatFields($this->db->getFieldData($table));
+
+		$this->keys = array_merge($this->keys, $this->formatKeys($this->db->getIndexData($table)));
+
+		$this->foreignKeys = $this->db->getForeignKeyData($table);
+
+		return $this;
+	}
+
+	/**
+	 * Called after `fromTable` and any actions, like `dropColumn`, etc,
+	 * to finalize the action. It creates a temp table, creates the new
+	 * table with modifications, and copies the data over to the new table.
+	 *
+	 * @return boolean
+	 */
+	public function run(): bool
+	{
+		$this->db->query('PRAGMA foreign_keys = OFF');
+
+		$this->db->transStart();
+
+		$this->forge->renameTable($this->tableName, "temp_{$this->tableName}");
+
+		$this->forge->reset();
+
+		$this->createTable();
+
+		$this->copyData();
+
+		$this->forge->dropTable("temp_{$this->tableName}");
+
+		$success = $this->db->transComplete();
+
+		$this->db->query('PRAGMA foreign_keys = ON');
+
+		return $success;
+	}
+
+	/**
+	 * Drops a column from the table.
+	 *
+	 * @param string $column
+	 *
+	 * @return \CodeIgniter\Database\SQLite3\Table
+	 */
+	public function dropColumn(string $column)
+	{
+		unset($this->fields[$column]);
+
+		return $this;
+	}
+
+	/**
+	 * Modifies a field, including changing data type,
+	 * renaming, etc.
+	 *
+	 * @param array $field
+	 *
+	 * @return \CodeIgniter\Database\SQLite3\Table
+	 */
+	public function modifyColumn(array $field)
+	{
+		$field = $field[0];
+
+		$oldName = $field['name'];
+		unset($field['name']);
+
+		$this->fields[$oldName] = $field;
+
+		return $this;
+	}
+
+	/**
+	 * Drops a foreign key from this table so that
+	 * it won't be recreated in the future.
+	 *
+	 * @param string $column
+	 *
+	 * @return \CodeIgniter\Database\SQLite3\Table
+	 */
+	public function dropForeignKey(string $column)
+	{
+		if (empty($this->foreignKeys))
+		{
+			return $this;
+		}
+
+		for ($i = 0; $i < count($this->foreignKeys); $i++)
+		{
+			if ($this->foreignKeys[$i]->table_name !== $this->tableName)
+			{
+				continue;
+			}
+
+			// The column name should be the first thing in the constraint name
+			if (strpos($this->foreignKeys[$i]->constraint_name, $column) !== 0)
+			{
+				continue;
+			}
+
+			unset($this->foreignKeys[$i]);
+		}
+
+		return $this;
+	}
+
+	/**
+	 * Creates the new table based on our current fields.
+	 *
+	 * @return mixed
+	 */
+	protected function createTable()
+	{
+		$this->dropIndexes();
+		$this->db->resetDataCache();
+
+		// Handle any modified columns.
+		$fields = [];
+		foreach ($this->fields as $name => $field)
+		{
+			if (isset($field['new_name']))
+			{
+				$fields[$field['new_name']] = $field;
+				continue;
+			}
+
+			$fields[$name] = $field;
+		}
+
+		$this->forge->addField($fields);
+
+		// Unique/Index keys
+		if (is_array($this->keys))
+		{
+			foreach ($this->keys as $key)
+			{
+				switch ($key['type'])
+				{
+					case 'primary':
+						$this->forge->addPrimaryKey($key['fields']);
+						break;
+					case 'unique':
+						$this->forge->addUniqueKey($key['fields']);
+						break;
+					case 'index':
+						$this->forge->addKey($key['fields']);
+						break;
+				}
+			}
+		}
+
+		// Foreign Keys
+
+		return $this->forge->createTable($this->tableName);
+	}
+
+	/**
+	 * Copies data from our old table to the new one,
+	 * taking care map data correctly based on any columns
+	 * that have been renamed.
+	 *
+	 * @return void
+	 */
+	protected function copyData()
+	{
+		$exFields  = [];
+		$newFields = [];
+
+		foreach ($this->fields as $name => $details)
+		{
+			// Are we modifying the column?
+			if (isset($details['new_name']))
+			{
+				$newFields[] = $details['new_name'];
+			}
+			else
+			{
+				$newFields[] = $name;
+			}
+
+			$exFields[] = $name;
+		}
+
+		$exFields  = implode(', ', $exFields);
+		$newFields = implode(', ', $newFields);
+
+		$this->db->query("INSERT INTO {$this->prefixedTableName}({$newFields}) SELECT {$exFields} FROM {$this->db->DBPrefix}temp_{$this->tableName}");
+	}
+
+	/**
+	 * Converts fields retrieved from the database to
+	 * the format needed for creating fields with Forge.
+	 *
+	 * @param array|boolean $fields
+	 *
+	 * @return mixed
+	 */
+	protected function formatFields($fields)
+	{
+		if (! is_array($fields))
+		{
+			return $fields;
+		}
+
+		$return = [];
+
+		foreach ($fields as $field)
+		{
+			$return[$field->name] = [
+				'type'     => $field->type,
+				'default'  => $field->default,
+				'nullable' => $field->nullable,
+			];
+
+			if ($field->primary_key)
+			{
+				$this->keys[$field->name] = [
+					'fields' => [$field->name],
+					'type'   => 'primary',
+				];
+			}
+		}
+
+		return $return;
+	}
+
+	/**
+	 * Converts keys retrieved from the database to
+	 * the format needed to create later.
+	 *
+	 * @param mixed $keys
+	 *
+	 * @return mixed
+	 */
+	protected function formatKeys($keys)
+	{
+		if (! is_array($keys))
+		{
+			return $keys;
+		}
+
+		$return = [];
+
+		foreach ($keys as $name => $key)
+		{
+			$return[$name] = [
+				'fields' => $key->fields,
+				'type'   => 'index',
+			];
+		}
+
+		return $return;
+	}
+
+	/**
+	 * Attempts to drop all indexes and constraints
+	 * from the database for this table.
+	 *
+	 * @return null|void
+	 */
+	protected function dropIndexes()
+	{
+		if (! is_array($this->keys) || ! count($this->keys))
+		{
+			return;
+		}
+
+		foreach ($this->keys as $name => $key)
+		{
+			if ($key['type'] === 'primary' || $key['type'] === 'unique')
+			{
+				continue;
+			}
+
+			$this->db->query("DROP INDEX IF EXISTS '{$name}'");
+		}
+	}
+}

system/Database/SQLite3/Utils.php

@@ -0,0 +1,73 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database\SQLite3;
+
+use CodeIgniter\Database\BaseUtils;
+use CodeIgniter\Database\Exceptions\DatabaseException;
+
+/**
+ * Utils for SQLite3
+ */
+class Utils extends BaseUtils
+{
+
+	/**
+	 * OPTIMIZE TABLE statement
+	 *
+	 * @var string
+	 */
+	protected $optimizeTable = 'REINDEX %s';
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Platform dependent version of the backup function.
+	 *
+	 * @param array|null $prefs
+	 *
+	 * @return mixed
+	 */
+	public function _backup(array $prefs = null)
+	{
+		throw new DatabaseException('Unsupported feature of the database platform you are using.');
+	}
+
+	//--------------------------------------------------------------------
+}

system/Database/Seeder.php

@@ -0,0 +1,228 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Database;
+
+use CodeIgniter\CLI\CLI;
+use CodeIgniter\Config\BaseConfig;
+
+/**
+ * Class Seeder
+ */
+class Seeder
+{
+
+	/**
+	 * The name of the database group to use.
+	 *
+	 * @var string
+	 */
+	protected $DBGroup;
+
+	/**
+	 * Where we can find the Seed files.
+	 *
+	 * @var string
+	 */
+	protected $seedPath;
+
+	/**
+	 * An instance of the main Database configuration
+	 *
+	 * @var BaseConfig
+	 */
+	protected $config;
+
+	/**
+	 * Database Connection instance
+	 *
+	 * @var BaseConnection
+	 */
+	protected $db;
+
+	/**
+	 * Database Forge instance.
+	 *
+	 * @var Forge
+	 */
+	protected $forge;
+
+	/**
+	 * If true, will not display CLI messages.
+	 *
+	 * @var boolean
+	 */
+	protected $silent = false;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Seeder constructor.
+	 *
+	 * @param BaseConfig     $config
+	 * @param BaseConnection $db
+	 */
+	public function __construct(BaseConfig $config, BaseConnection $db = null)
+	{
+		$this->seedPath = $config->filesPath ?? APPPATH . 'Database/';
+
+		if (empty($this->seedPath))
+		{
+			throw new \InvalidArgumentException('Invalid filesPath set in the Config\Database.');
+		}
+
+		$this->seedPath = rtrim($this->seedPath, '/') . '/Seeds/';
+
+		if (! is_dir($this->seedPath))
+		{
+			throw new \InvalidArgumentException('Unable to locate the seeds directory. Please check Config\Database::filesPath');
+		}
+
+		$this->config = & $config;
+
+		if (is_null($db))
+		{
+			$db = \Config\Database::connect($this->DBGroup);
+		}
+
+		$this->db = & $db;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Loads the specified seeder and runs it.
+	 *
+	 * @param string $class
+	 *
+	 * @throws \InvalidArgumentException
+	 */
+	public function call(string $class)
+	{
+		if (empty($class))
+		{
+			throw new \InvalidArgumentException('No Seeder was specified.');
+		}
+
+		$path = str_replace('.php', '', $class) . '.php';
+
+		// If we have namespaced class, simply try to load it.
+		if (strpos($class, '\\') !== false)
+		{
+			$seeder = new $class($this->config);
+		}
+		// Otherwise, try to load the class manually.
+		else
+		{
+			$path = $this->seedPath . $path;
+
+			if (! is_file($path))
+			{
+				throw new \InvalidArgumentException('The specified Seeder is not a valid file: ' . $path);
+			}
+
+			// Assume the class has the correct namespace
+			$class = APP_NAMESPACE . '\Database\Seeds\\' . $class;
+
+			if (! class_exists($class, false))
+			{
+				require_once $path;
+			}
+
+			$seeder = new $class($this->config);
+		}
+
+		$seeder->run();
+
+		unset($seeder);
+
+		if (is_cli() && ! $this->silent)
+		{
+			CLI::write("Seeded: {$class}", 'green');
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Sets the location of the directory that seed files can be located in.
+	 *
+	 * @param string $path
+	 *
+	 * @return Seeder
+	 */
+	public function setPath(string $path)
+	{
+		$this->seedPath = rtrim($path, '/') . '/';
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Sets the silent treatment.
+	 *
+	 * @param boolean $silent
+	 *
+	 * @return Seeder
+	 */
+	public function setSilent(bool $silent)
+	{
+		$this->silent = $silent;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Run the database seeds. This is where the magic happens.
+	 *
+	 * Child classes must implement this method and take care
+	 * of inserting their data here.
+	 *
+	 * @return mixed
+	 */
+	public function run()
+	{
+	}
+
+	//--------------------------------------------------------------------
+}