<?php
/* SVN FILE: $Id$ */

/**
 * {@link http://pear.php.net/package/DB PEAR::DB} layer for DBO.
 *
 * Long description for file
 *
 * PHP versions 4 and 5
 *
 * CakePHP :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright (c) 2006, Cake Software Foundation, Inc.
 *                     1785 E. Sahara Avenue, Suite 490-204
 *                     Las Vegas, Nevada 89104
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @filesource
 * @copyright    Copyright (c) 2006, Cake Software Foundation, Inc.
 * @link         http://www.cakefoundation.org/projects/info/cakephp CakePHP Project
 * @package      cake
 * @subpackage   cake.cake.libs.model.datasources.dbo
 * @since        CakePHP v 0.2.9
 * @version      $Revision$
 * @modifiedby   $LastChangedBy$
 * @lastmodified $Date$
 * @license      http://www.opensource.org/licenses/mit-license.php The MIT License
 */

/**
 * Create an include path required PEAR libraries.
 */
uses('model'.DS.'datasources'.DS.'dbo_source');
ini_set('include_path', ini_get('include_path') . PATH_SEPARATOR . PEAR);
vendor('Pear/DB');

/**
 * {@link http://pear.php.net/package/DB PEAR::DB} layer for DBO.
 *
 * Long description for class
 *
 * @package    cake
 * @subpackage cake.cake.libs.model.datasources.dbo
 * @since      CakePHP v 0.2.9
 */
class DBO_Pear extends DboSource
{

/**
 * PEAR::DB object with which we connect.
 *
 * @var DB The connection object.
 * @access private
 */
    var $_pear = null;

/**
 * Connects to the database using options in the given configuration array.
 *
 * @param array $config Configuration array for connecting
 * @return boolean True if the database could be connected, else false
 */
    function connect ($config)
    {
      $this->config = $config;

      $dsn = $config['driver'].'://'.$config['login'].':'.$config['password'].'@'.$config['host'].'/'.$config['database'];
      $options = array(
         'debug'        => DEBUG-1,
         'portability' => DB_PORTABILITY_ALL,
      );

      $this->_pear =& DB::connect($dsn, $options);
      $this->connected = $this->_pear? true: false;

      return !(PEAR::isError($this->_pear));

    }

/**
 * Disconnects from database.
 *
 * @return boolean True if the database could be disconnected, else false
 */
    function disconnect ()
    {
      die('Please implement DBO::disconnect() first.');
    }

/**
 * Executes given SQL statement.
 *
 * @param string $sql SQL statement
 * @return resource Result resource identifier
 */
    function execute ($sql)
    {
      return $this->_pear->query($sql);
    }

/**
 * Returns a row from given resultset as an array .
 *
 * @return array The fetched row as an array
 */
    function fetchRow ()
    {
      return $this->_result->fetchRow(DB_FETCHMODE_ASSOC);
    }

/**
 * Returns an array of tables in the database. If there are no tables, an error is raised and the application exits.
 * :WARNING: :TODO: POSTGRESQL & MYSQL ONLY! PEAR::DB doesn't support universal table listing.
 *
 * @return array Array of tablenames in the database
 */
    function tablesList ()
    {
      $driver = $this->config['driver'];
      $tables = array();

      if ('postgres' == $driver)
      {
         $sql = "SELECT a.relname AS name
            FROM pg_class a, pg_user b
            WHERE ( relkind = 'r') and relname !~ '^pg_' AND relname !~ '^sql_'
            AND relname !~ '^xin[vx][0-9]+' AND b.usesysid = a.relowner
            AND NOT (EXISTS (SELECT viewname FROM pg_views WHERE viewname=a.relname));";

         $result = $this->all($sql);
         foreach ($result as $item)
         {
            $tables[] = $item['name'];
         }
      }
      elseif ('mysql' == $driver)
      {
         $result = array();

         $result = mysql_list_tables($this->config['database']);
         while ($item = mysql_fetch_array($result))
         {
            $tables[] = $item[0];
         }
      }
      else
      {
         die('Please implement DBO_Pear::tablesList() for your database driver.');
      }


      if (!$result)
      {
         trigger_error(ERROR_NO_TABLE_LIST, E_USER_ERROR);
         exit;
      }
      else
      {
         return $tables;
      }
    }

/**
 * Returns an array of the fields in given table name.
 *
 * @param string $tableName Name of database table to inspect
 * @return array Fields in table. Keys are name and type
 */
    function fields ($tableName)
    {
      $data = $this->_pear->tableInfo($tableName);
      $fields = false;

      foreach ($data as $item)
         $fields[] = array('name'=>$item['name'], 'type'=>$item['type']);

      return $fields;
    }

/**
 * Returns a quoted and escaped string of $data for use in an SQL statement.
 *
 * @param string $data String to be prepared for use in an SQL statement
 * @return string Quoted and escaped
 */
    function prepareValue ($data)
    {
      return $this->_pear->quoteSmart($data);
    }

/**
 * Returns a formatted error message from previous database operation.
 *
 * @return string Error message
 */
    function lastError ()
    {
      return PEAR::isError($this->_result)? $this->_result->getMessage(): null;
    }

/**
 * Returns number of affected rows in previous database operation. If no previous operation exists, this returns false.
 *
 * @return int Number of affected rows
 */
    function lastAffected ()
    {
      return $this->_pear->affectedRows();
    }

/**
 * Returns number of rows in previous resultset. If no previous resultset exists,
 * this returns false.
 *
 * @return int Number of rows in resultset
 */
    function lastNumRows ()
    {
      if (method_exists($this->_result, 'numRows'))
      {
         return $this->_result->numRows();
      }
      else
      {
         return false;
      }
    }

/**
 * Returns the ID generated from the previous INSERT operation.
 *
 * @param string $table Name of the database table
 * @return int
 */
    function lastInsertId ($table)
    {
      return $this->field('id', "SELECT MAX(id) FROM {$table}");
    }

/**
 * Returns a limit statement in the correct format for the particular database.
 *
 * @param int $limit Limit of results returned
 * @param int $offset Offset from which to start results
 * @return string SQL limit/offset statement
 */
    function selectLimit ($limit, $offset='0')
    {
      return ' ' . $this->_pear->modifyLimitQuery('', $offset, $limit);
    }

}

?>