sqlite.php

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<?php
// vim: set et ts=4 sw=4 fdm=marker:
// +----------------------------------------------------------------------+
// | PHP versions 4 and 5                                                 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox,                 |
// | Stig. S. Bakken, Lukas Smith                                         |
// | All rights reserved.                                                 |
// +----------------------------------------------------------------------+
// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
// | API as well as database abstraction for PHP applications.            |
// | This LICENSE is in the BSD license style.                            |
// |                                                                      |
// | Redistribution and use in source and binary forms, with or without   |
// | modification, are permitted provided that the following conditions   |
// | are met:                                                             |
// |                                                                      |
// | Redistributions of source code must retain the above copyright       |
// | notice, this list of conditions and the following disclaimer.        |
// |                                                                      |
// | Redistributions in binary form must reproduce the above copyright    |
// | notice, this list of conditions and the following disclaimer in the  |
// | documentation and/or other materials provided with the distribution. |
// |                                                                      |
// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
// | Lukas Smith nor the names of his contributors may be used to endorse |
// | or promote products derived from this software without specific prior|
// | written permission.                                                  |
// |                                                                      |
// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
// | POSSIBILITY OF SUCH DAMAGE.                                          |
// +----------------------------------------------------------------------+
// | Author: Lukas Smith <[e-mail]>                           |
// +----------------------------------------------------------------------+
//
// $Id: sqlite.php,v 1.158 2008/03/08 14:18:39 quipo Exp $
//

/**
 * MDB2 SQLite driver
 *
 * @package MDB2
 * @category Database
 * @author  Lukas Smith <[e-mail]>
 */
class MDB2_Driver_sqlite extends MDB2_Driver_Common
{
    // {{{ properties
    var $string_quoting = array('start' => "'", 'end' => "'", 'escape' => "'", 'escape_pattern' => false);

    var $identifier_quoting = array('start' => '"', 'end' => '"', 'escape' => '"');

    var $_lasterror = '';

    var $fix_assoc_fields_names = false;

    // }}}
    // {{{ constructor

    /**
     * Constructor
     */
    function __construct()
    {
        parent::__construct();

        $this->phptype = 'sqlite';
        $this->dbsyntax = 'sqlite';

        $this->supported['sequences'] = 'emulated';
        $this->supported['indexes'] = true;
        $this->supported['affected_rows'] = true;
        $this->supported['summary_functions'] = true;
        $this->supported['order_by_text'] = true;
        $this->supported['current_id'] = 'emulated';
        $this->supported['limit_queries'] = true;
        $this->supported['LOBs'] = true;
        $this->supported['replace'] = true;
        $this->supported['transactions'] = true;
        $this->supported['savepoints'] = false;
        $this->supported['sub_selects'] = true;
        $this->supported['triggers'] = true;
        $this->supported['auto_increment'] = true;
        $this->supported['primary_key'] = false; // requires alter table implementation
        $this->supported['result_introspection'] = false; // not implemented
        $this->supported['prepared_statements'] = 'emulated';
        $this->supported['identifier_quoting'] = true;
        $this->supported['pattern_escaping'] = false;
        $this->supported['new_link'] = false;

        $this->options['DBA_username'] = false;
        $this->options['DBA_password'] = false;
        $this->options['base_transaction_name'] = '___php_MDB2_sqlite_auto_commit_off';
        $this->options['fixed_float'] = 0;
        $this->options['database_path'] = '';
        $this->options['database_extension'] = '';
        $this->options['server_version'] = '';
        $this->options['max_identifiers_length'] = 128; //no real limit
    }

    // }}}
    // {{{ errorInfo()

    /**
     * This method is used to collect information about an error
     *
     * @param integer $error
     * @return array
     * @access public
     */
    function errorInfo($error = null)
    {
        $native_code = null;
        if ($this->connection) {
            $native_code = @sqlite_last_error($this->connection);
        }
        $native_msg = $this->_lasterror
            ? html_entity_decode($this->_lasterror) : @sqlite_error_string($native_code);
            
        // PHP 5.2+ prepends the function name to $php_errormsg, so we need
        // this hack to work around it, per bug #9599.
        $native_msg = preg_replace('/^sqlite[a-z_]+\(\)[^:]*: /', '', $native_msg);

        if (is_null($error)) {
            static $error_regexps;
            if (empty($error_regexps)) {
                $error_regexps = array(
                    '/^no such table:/' => MDB2_ERROR_NOSUCHTABLE,
                    '/^no such index:/' => MDB2_ERROR_NOT_FOUND,
                    '/^(table|index) .* already exists$/' => MDB2_ERROR_ALREADY_EXISTS,
                    '/PRIMARY KEY must be unique/i' => MDB2_ERROR_CONSTRAINT,
                    '/is not unique/' => MDB2_ERROR_CONSTRAINT,
                    '/columns .* are not unique/i' => MDB2_ERROR_CONSTRAINT,
                    '/uniqueness constraint failed/' => MDB2_ERROR_CONSTRAINT,
                    '/may not be NULL/' => MDB2_ERROR_CONSTRAINT_NOT_NULL,
                    '/^no such column:/' => MDB2_ERROR_NOSUCHFIELD,
                    '/no column named/' => MDB2_ERROR_NOSUCHFIELD,
                    '/column not present in both tables/i' => MDB2_ERROR_NOSUCHFIELD,
                    '/^near ".*": syntax error$/' => MDB2_ERROR_SYNTAX,
                    '/[0-9]+ values for [0-9]+ columns/i' => MDB2_ERROR_VALUE_COUNT_ON_ROW,
                 );
            }
            foreach ($error_regexps as $regexp => $code) {
                if (preg_match($regexp, $native_msg)) {
                    $error = $code;
                    break;
                }
            }
        }
        return array($error, $native_code, $native_msg);
    }

    // }}}
    // {{{ escape()

    /**
     * Quotes a string so it can be safely used in a query. It will quote
     * the text so it can safely be used within a query.
     *
     * @param   string  the input string to quote
     * @param   bool    escape wildcards
     *
     * @return  string  quoted string
     *
     * @access  public
     */
    function escape($text, $escape_wildcards = false)
    {
        $text = @sqlite_escape_string($text);
        return $text;
    }

    // }}}
    // {{{ beginTransaction()

    /**
     * Start a transaction or set a savepoint.
     *
     * @param   string  name of a savepoint to set
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */
    function beginTransaction($savepoint = null)
    {
        $this->debug('Starting transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
        if (!is_null($savepoint)) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'savepoints are not supported', __FUNCTION__);
        } elseif ($this->in_transaction) {
            return MDB2_OK;  //nothing to do
        }
        if (!$this->destructor_registered && $this->opened_persistent) {
            $this->destructor_registered = true;
            register_shutdown_function('MDB2_closeOpenTransactions');
        }
        $query = 'BEGIN TRANSACTION '.$this->options['base_transaction_name'];
        $result =& $this->_doQuery($query, true);
        if (PEAR::isError($result)) {
            return $result;
        }
        $this->in_transaction = true;
        return MDB2_OK;
    }

    // }}}
    // {{{ commit()

    /**
     * Commit the database changes done during a transaction that is in
     * progress or release a savepoint. This function may only be called when
     * auto-committing is disabled, otherwise it will fail. Therefore, a new
     * transaction is implicitly started after committing the pending changes.
     *
     * @param   string  name of a savepoint to release
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */
    function commit($savepoint = null)
    {
        $this->debug('Committing transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
        if (!$this->in_transaction) {
            return $this->raiseError(MDB2_ERROR_INVALID, null, null,
                'commit/release savepoint cannot be done changes are auto committed', __FUNCTION__);
        }
        if (!is_null($savepoint)) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'savepoints are not supported', __FUNCTION__);
        }

        $query = 'COMMIT TRANSACTION '.$this->options['base_transaction_name'];
        $result =& $this->_doQuery($query, true);
        if (PEAR::isError($result)) {
            return $result;
        }
        $this->in_transaction = false;
        return MDB2_OK;
    }

    // }}}
    // {{{

    /**
     * Cancel any database changes done during a transaction or since a specific
     * savepoint that is in progress. This function may only be called when
     * auto-committing is disabled, otherwise it will fail. Therefore, a new
     * transaction is implicitly started after canceling the pending changes.
     *
     * @param   string  name of a savepoint to rollback to
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */
    function rollback($savepoint = null)
    {
        $this->debug('Rolling back transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
        if (!$this->in_transaction) {
            return $this->raiseError(MDB2_ERROR_INVALID, null, null,
                'rollback cannot be done changes are auto committed', __FUNCTION__);
        }
        if (!is_null($savepoint)) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'savepoints are not supported', __FUNCTION__);
        }

        $query = 'ROLLBACK TRANSACTION '.$this->options['base_transaction_name'];
        $result =& $this->_doQuery($query, true);
        if (PEAR::isError($result)) {
            return $result;
        }
        $this->in_transaction = false;
        return MDB2_OK;
    }

    // }}}
    // {{{ function setTransactionIsolation()

    /**
     * Set the transacton isolation level.
     *
     * @param   string  standard isolation level
     *                  READ UNCOMMITTED (allows dirty reads)
     *                  READ COMMITTED (prevents dirty reads)
     *                  REPEATABLE READ (prevents nonrepeatable reads)
     *                  SERIALIZABLE (prevents phantom reads)
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     * @since   2.1.1
     */
    function setTransactionIsolation($isolation)
    {
        $this->debug('Setting transaction isolation level', __FUNCTION__, array('is_manip' => true));
        switch ($isolation) {
        case 'READ UNCOMMITTED':
            $isolation = 0;
            break;
        case 'READ COMMITTED':
        case 'REPEATABLE READ':
        case 'SERIALIZABLE':
            $isolation = 1;
            break;
        default:
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'isolation level is not supported: '.$isolation, __FUNCTION__);
        }

        $query = "PRAGMA read_uncommitted=$isolation";
        return $this->_doQuery($query, true);
    }

    // }}}
    // {{{ getDatabaseFile()

    /**
     * Builds the string with path+dbname+extension
     *
     * @return string full database path+file
     * @access protected
     */
    function _getDatabaseFile($database_name)
    {
        if ($database_name === '' || $database_name === ':memory:') {
            return $database_name;
        }
        return $this->options['database_path'].$database_name.$this->options['database_extension'];
    }

    // }}}
    // {{{ connect()

    /**
     * Connect to the database
     *
     * @return true on success, MDB2 Error Object on failure
     **/
    function connect()
    {
        $database_file = $this->_getDatabaseFile($this->database_name);
        if (is_resource($this->connection)) {
            //if (count(array_diff($this->connected_dsn, $this->dsn)) == 0
            if (MDB2::areEquals($this->connected_dsn, $this->dsn)
                && $this->connected_database_name == $database_file
                && $this->opened_persistent == $this->options['persistent']
            ) {
                return MDB2_OK;
            }
            $this->disconnect(false);
        }

        if (!PEAR::loadExtension($this->phptype)) {
            return $this->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                'extension '.$this->phptype.' is not compiled into PHP', __FUNCTION__);
        }

        if (!empty($this->database_name)) {
            if ($database_file !== ':memory:') {