Subversion-Projekte lars-tiefland.php_share

<?php

/**

 * This file contains the class XML_Query2XML_Driver_DB.

 *

 * PHP version 5

 *

 * @category  XML

 * @package   XML_Query2XML

 * @author    Lukas Feiler <lukas.feiler@lukasfeiler.com>

 * @copyright 2006 Lukas Feiler

 * @license   http://www.gnu.org/copyleft/lesser.html  LGPL Version 2.1

 * @version   CVS: $Id: DB.php 276639 2009-03-01 13:17:08Z lukasfeiler $

 * @link      http://pear.php.net/package/XML_Query2XML

 */

/**

 * XML_Query2XML_Driver_DB extends XML_Query2XML_Driver.

 */

require_once 'XML/Query2XML.php';

/**

 * As the method PEAR::isError() is used within XML_Query2XML_Driver_DB

 * we require PEAR.php.

 */

require_once 'PEAR.php';

/**

 * Driver for the database abstraction layer PEAR DB.

 *

 * usage:

 * <code>

 * $driver = XML_Query2XML_Driver::factory(DB::connect(...));

 * </code>

 *

 * @category  XML

 * @package   XML_Query2XML

 * @author    Lukas Feiler <lukas.feiler@lukasfeiler.com>

 * @copyright 2006 Lukas Feiler

 * @license   http://www.gnu.org/copyleft/lesser.html  LGPL Version 2.1

 * @version   Release: 1.7.2

 * @link      http://pear.php.net/package/XML_Query2XML

 * @since     Release 1.5.0RC1

 */

class XML_Query2XML_Driver_DB extends XML_Query2XML_Driver

{

    /**

     * In instance of a class that extends DB_common.

     * @var DB_common

     */

    private $_db = null;

    /**

     * Constructor

     *

     * @param DB_Common $db An instance of a class that extends DB_Common.

     *

     * @throws XML_Query2XML_DBException If the fetch mode cannot be set to

     *                               DB_FETCHMODE_ASSOC.

     */

    public function __construct(DB_common $db)

    {

        $fetchModeError = $db->setFetchMode(DB_FETCHMODE_ASSOC);

        if (PEAR::isError($fetchModeError)) {

            // no unit tests for this one

            throw new XML_Query2XML_DBException(

                'Could not set fetch mode to DB_FETCHMODE_ASSOC: '

                . $fetchModeError->toString()

            );

        }

        $this->_db = $db;

    }

    /**

     * Pre-processes a query specification and returns a string representation

     * of the query.

     * This method will call parent::preprocessQuery(). Additionally it will

     * verify $query['limit'] and $query['offset'].

     *

     * @param mixed  &$query     A string or an array containing the element 'query'.

     * @param string $configPath The config path; used for exception messages.

     *

     * @return string The query statement as a string.

     * @throws XML_Query2XML_ConfigException If $query['limit'] or $query['offset']

     *                                       is set but not numeric. This exception

     *                                       might also bubble up from

     *                                       parent::preprocessQuery().

     */

    public function preprocessQuery(&$query, $configPath)

    {

        /*

         * This will make $query an array if it is not already.

         * We'll ignore preprocessQuery()'s return value here.

         */

        parent::preprocessQuery($query, $configPath);

        foreach (array('limit', 'offset') as $sqlOption) {

            if (isset($query[$sqlOption])) {

                if (!is_numeric($query[$sqlOption])) {

                    /*

                     * unit test: getXML/

                     *  offsetlimit_throwConfigException_limit_not_numeric.phpt

                     *  offsetlimit_throwConfigException_offset_not_numeric.phpt

                     */

                    throw new XML_Query2XML_ConfigException(

                        $configPath . '[' . $sqlOption

                        . ']: integer expected, '

                        . gettype($query[$sqlOption]) . ' given.'

                    );

                }

            }

        }

        $queryString = $query['query'];

        if (isset($query['limit'])) {

            if ($query['limit'] == 0) {

                // setting limit to 0 is like not setting it at all

                unset($query['limit']);

            } else {

                if (!isset($query['offset'])) {

                    // offset defaults to 0

                    $query['offset'] = 0;

                }

                $queryString .= '; LIMIT:' . $query['limit'];

                $queryString .= '; OFFSET:' . $query['offset'];

                $query['query'] = $this->_db->modifyLimitQuery(

                    $query['query'],

                    $query['offset'],

                    $query['limit']

                );

            }

        }

        return $queryString;

    }

    /**

     * Execute a SQL SELECT stement and fetch all records from the result set.

     *

     * @param mixed  $sql        The SQL query as an array containing the

     *                           element 'query'.

     * @param string $configPath The config path; used for exception messages.

     *

     * @return array An array of records.

     * @throws XML_Query2XML_DBException If a database related error occures.

     * @see XML_Query2XML_Driver::getAllRecords()

     */

    public function getAllRecords($sql, $configPath)

    {

        if (isset($sql['limit']) && $sql['limit'] < 0) {

            return array();

        }

        $result  =& $this->_prepareAndExecute($sql, $configPath);

        $records = array();

        while ($record = $result->fetchRow()) {

            if (PEAR::isError($record)) {

                // no unit test for this exception as it cannot be produced easily

                throw new XML_Query2XML_DBException(

                    $configPath . ': Could not fetch rows for the following '

                    . 'SQL query: ' . $sql['query'] . '; '

                    . $record->toString()

                );

            }

            $records[] = $record;

        }

        $result->free();

        return $records;

    }

    /**

     * Private method that will use DB_Common::prepare() & DB_Common::execute()

     * to run an SQL query.

     *

     * @param mixed  $sql        An associative array with a 'query' element.

     * @param string $configPath The config path used for exception messages.

     *

     * @return DB_result

     * @throws XML_Query2XML_DBException If a database related error occures.

     */

    private function _prepareAndExecute($sql, $configPath)

    {

        $query = $sql['query'];

        if (isset($this->_preparedQueries[$query])) {

            $queryHandle = $this->_preparedQueries[$query];

        } else {

            // PREPARE

            $queryHandle = $this->_db->prepare($query);

            if (PEAR::isError($queryHandle)) {

                /*

                 * No unit test for this exception as DB's mysql and pgsql

                 * drivers never return a PEAR error from prepare().

                 */

                throw new XML_Query2XML_DBException(

                    $configPath . ': Could not prepare the following SQL query: '

                    . $query . '; ' . $queryHandle->toString()

                );

            }

            $this->_preparedQueries[$query] =& $queryHandle;

        }

        // EXECUTE

        if (isset($sql['data'])) {

            $result = $this->_db->execute($queryHandle, $sql['data']);

        } else {

            $result = $this->_db->execute($queryHandle);

        }

        if (PEAR::isError($result)) {

            /*

             * unit test: DB/_prepareAndExecute/

             *  throwDBException_complexQuery.phpt

             */

            throw new XML_Query2XML_DBException(

                $configPath . ': Could not execute the following SQL query: '

                . $query . '; ' . $result->toString()

            );

        }

        if (!($result instanceof DB_result)) {

            /*

             * unit tests: DB/getXML/

             *  throwDBException_nullResultSet_complexQuery_multipleRecords.phpt

             *  throwDBException_nullResultSet_complexQuery_singleRecord.phpt

             */

            throw new XML_Query2XML_DBException(

                $configPath . ': the following SQL query returned no '

                . 'result set: ' . $query

            );

        }

        return $result;

    }

}

?>