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

/**
 * PostgreSQL layer for DBO.
 * 
 * Long description for file
 *
 * PHP versions 4 and 5
 *
 * CakePHP :  Rapid Development Framework <http://www.cakephp.org/>
 * Copyright (c) 2005, CakePHP Authors/Developers
 *
 * Author(s): Michal Tatarynowicz aka Pies <tatarynowicz@gmail.com>
 *            Larry E. Masters aka PhpNut <nut@phpnut.com>
 *            Kamil Dzielinski aka Brego <brego.dk@gmail.com>
 *
 *  Licensed under The MIT License
 *  Redistributions of files must retain the above copyright notice.
 *
 * @filesource 
 * @author       CakePHP Authors/Developers
 * @copyright    Copyright (c) 2005, CakePHP Authors/Developers
 * @link         https://trac.cakephp.org/wiki/Authors Authors/Developers
 * @package      cake
 * @subpackage   cake.libs.dbo
 * @since        CakePHP v 0.9.1.114
 * @version      $Revision$
 * @modifiedby   $LastChangedBy$
 * @lastmodified $Date$
 * @license      http://www.opensource.org/licenses/mit-license.php The MIT License
 */

/**
  * Include DBO.
  */
uses('dbo');

/**
 * PostgreSQL layer for DBO.
 * 
 * Long description for class
 *
 * @package    cake
 * @subpackage cake.libs.dbo
 * @since      CakePHP v 0.9.1.114
 */
class DBO_Postgres extends DBO 
{
   
/**
  * Connects to the database using options in the given configuration array.
  *
  * @param array $config Configuration array for connecting
  * @return True if successfully connected.
  */
   function connect ($config) 
   {
      if ($config) 
      {
         $this->config = $config;
         $this->_conn = pg_pconnect("host={$config['host']} dbname={$config['database']} user={$config['login']} password={$config['password']}");
      }
      $this->connected = $this->_conn? true: false;

      if($this->connected)
         return true;
      else
      {
         //die('Could not connect to DB.');
      }
   }

/**
  * Disconnects from database.
  *
  * @return boolean True if the database could be disconnected, else false
  */
   function disconnect () 
   {
      return pg_close($this->_conn);
   }

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

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

/**
  * Returns an array of tables in the database. If there are no tables, an error is raised and the application exits.
  *
  * @return array Array of tablenames in the database
  */
   function tablesList () 
   {
      $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);

      if (!$result) 
      {
         trigger_error(ERROR_NO_TABLE_LIST, E_USER_ERROR);
         exit;
      }
      else 
      {
         $tables = array();
         foreach ($result as $item) $tables[] = $item['name'];
         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)
   {
      $sql = "SELECT c.relname, a.attname, t.typname FROM pg_class c, pg_attribute a, pg_type t WHERE c.relname = '{$tableName}' AND a.attnum > 0 AND a.attrelid = c.oid AND a.atttypid = t.oid";
      
      $fields = false;
      foreach ($this->all($sql) as $field) {
         $fields[] = array(
            'name' => $field['attname'],
            'type' => $field['typname']);
      }

      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 "'".pg_escape_string($data)."'";
   }

/**
  * Returns a formatted error message from previous database operation.
  *
  * @return string Error message
  */
   function lastError () 
   {
      $last_error = pg_last_error($this->_conn);
      return $last_error? $last_error: 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 $this->_result? pg_affected_rows($this->_result): false;
   }

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

/**
  * Returns the ID generated from the previous INSERT operation.
  *
  * @param string $table Name of the database table
  * @param string $field Name of the ID database field. Defaults to "id"
  * @return int 
  */
   function lastInsertId ($table, $field='id') 
   {
      $sql = "SELECT CURRVAL('{$table}_{$field}_seq') AS max";
      $res = $this->rawQuery($sql);
      $data = $this->fetchRow($res);
      return $data['max'];
   }

/**
 * 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, $offset=null)
   {
      return " LIMIT {$limit}".($offset? " OFFSET {$offset}": null);
   }

}

?>