system/database/drivers/pdo/subdrivers/pdo_sqlite_forge.php
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2019 - 2022, 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 EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
* @copyright Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
* @copyright Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 3.0.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* PDO SQLite Forge Class
*
* @category Database
* @author EllisLab Dev Team
* @link https://codeigniter.com/userguide3/database/
*/
class CI_DB_pdo_sqlite_forge extends CI_DB_pdo_forge {
/**
* CREATE TABLE IF statement
*
* @var string
*/
protected $_create_table_if = 'CREATE TABLE IF NOT EXISTS';
/**
* DROP TABLE IF statement
*
* @var string
*/
protected $_drop_table_if = 'DROP TABLE IF EXISTS';
/**
* UNSIGNED support
*
* @var bool|array
*/
protected $_unsigned = FALSE;
/**
* NULL value representation in CREATE/ALTER TABLE statements
*
* @var string
*/
protected $_null = 'NULL';
// --------------------------------------------------------------------
/**
* Class constructor
*
* @param object &$db Database object
* @return void
*/
public function __construct(&$db)
{
parent::__construct($db);
if (version_compare($this->db->version(), '3.3', '<'))
{
$this->_create_table_if = FALSE;
$this->_drop_table_if = FALSE;
}
}
// --------------------------------------------------------------------
/**
* Create database
*
* @param string $db_name (ignored)
* @return bool
*/
public function create_database($db_name)
{
// 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 $db_name (ignored)
* @return bool
*/
public function drop_database($db_name)
{
// In SQLite, a database is dropped when we delete a file
if (file_exists($this->db->database))
{
// We need to close the pseudo-connection first
$this->db->close();
if ( ! @unlink($this->db->database))
{
return $this->db->db_debug ? $this->db->display_error('db_unable_to_drop') : FALSE;
}
elseif ( ! empty($this->db->data_cache['db_names']))
{
$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
if ($key !== FALSE)
{
unset($this->db->data_cache['db_names'][$key]);
}
}
return TRUE;
}
return $this->db->db_debug ? $this->db->display_error('db_unable_to_drop') : FALSE;
}
// --------------------------------------------------------------------
/**
* ALTER TABLE
*
* @param string $alter_type ALTER type
* @param string $table Table name
* @param mixed $field Column definition
* @return string|string[]
*/
protected function _alter_table($alter_type, $table, $field)
{
if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
{
// drop_column():
// BEGIN TRANSACTION;
// CREATE TEMPORARY TABLE t1_backup(a,b);
// INSERT INTO t1_backup SELECT a,b FROM t1;
// DROP TABLE t1;
// CREATE TABLE t1(a,b);
// INSERT INTO t1 SELECT a,b FROM t1_backup;
// DROP TABLE t1_backup;
// COMMIT;
return FALSE;
}
return parent::_alter_table($alter_type, $table, $field);
}
// --------------------------------------------------------------------
/**
* Process column
*
* @param array $field
* @return string
*/
protected function _process_column($field)
{
return $this->db->escape_identifiers($field['name'])
.' '.$field['type']
.$field['auto_increment']
.$field['null']
.$field['unique']
.$field['default'];
}
// --------------------------------------------------------------------
/**
* Field attribute TYPE
*
* Performs a data type mapping between different databases.
*
* @param array &$attributes
* @return void
*/
protected function _attr_type(&$attributes)
{
switch (strtoupper($attributes['TYPE']))
{
case 'ENUM':
case 'SET':
$attributes['TYPE'] = 'TEXT';
return;
default: return;
}
}
// --------------------------------------------------------------------
/**
* Field attribute AUTO_INCREMENT
*
* @param array &$attributes
* @param array &$field
* @return void
*/
protected function _attr_auto_increment(&$attributes, &$field)
{
if ( ! empty($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->primary_keys = array();
}
}
}