Subversion-Projekte lars-tiefland.ci

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2018, 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      EllisLab Dev Team
 * @copyright   Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright   Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
 * @license     http://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');

/**
 * SQLite3 Forge Class
 *
 * @category    Database
 * @author      Andrey Andreev
 * @link        https://codeigniter.com/user_guide/database/
 */
class CI_DB_sqlite3_forge extends CI_DB_forge {

        /**
         * 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  $db_name
         * @return      bool
         */
        public function create_database($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
         *
         * @todo        implement drop_column(), modify_column()
         * @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();
                }
        }

}