/system/database/drivers/postgre/postgre_driver.php

<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 4.3.2 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2006, EllisLab, Inc.

 * @license		http://codeigniter.com/user_guide/license.html

 * @link		http://codeigniter.com

 * @since		Version 1.0

 * @filesource

 */



// ------------------------------------------------------------------------



/**

 * Postgre Database Adapter Class

 *

 * Note: _DB is an extender class that the app controller

 * creates dynamically based on whether the active record

 * class is being used or not.

 *

 * @package		CodeIgniter

 * @subpackage	Drivers

 * @category	Database

 * @author		ExpressionEngine Dev Team

 * @link		http://codeigniter.com/user_guide/database/

 */

class CI_DB_postgre_driver extends CI_DB {



	/**

	 * The syntax to count rows is slightly different across different

	 * database engines, so this string appears in each driver and is

	 * used for the count_all() and count_all_results() functions.

	 */

	var $_count_string = "SELECT COUNT(*) AS ";

	var $_random_keyword = ' RANDOM()'; // database specific random keyword



	/**

	 * Non-persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_connect()

	{

		$port = ($this->port == '') ? '' : " port=".$this->port;

		

		return @pg_connect("host=".$this->hostname.$port." dbname=".$this->database." user=".$this->username." password=".$this->password);

	}



	// --------------------------------------------------------------------



	/**

	 * Persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_pconnect()

	{

		$port = ($this->port == '') ? '' : " port=".$this->port;



		return @pg_pconnect("host=".$this->hostname.$port." dbname=".$this->database." user=".$this->username." password=".$this->password);

	}

	

	// --------------------------------------------------------------------



	/**

	 * Select the database

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_select()

	{

		// Not needed for Postgre so we'll return TRUE

		return TRUE;

	}



	// --------------------------------------------------------------------



	/**

	 * Set client character set

	 *

	 * @access	public

	 * @param	string

	 * @param	string

	 * @return	resource

	 */

	function db_set_charset($charset, $collation)

	{

		// TODO - add support if needed

		return TRUE;

	}



	// --------------------------------------------------------------------

	

	/**

	 * Version number query string

	 *

	 * @access	public

	 * @return	string

	 */

	function _version()

	{

		return "SELECT version() AS ver";

	}



	// --------------------------------------------------------------------



	/**

	 * Execute the query

	 *

	 * @access	private called by the base class

	 * @param	string	an SQL query

	 * @return	resource

	 */	

	function _execute($sql)

	{

		$sql = $this->_prep_query($sql);

		return @pg_query($this->conn_id, $sql);

	}

	

	// --------------------------------------------------------------------



	/**

	 * Prep the query

	 *

	 * If needed, each database adapter can prep the query string

	 *

	 * @access	private called by execute()

	 * @param	string	an SQL query

	 * @return	string

	 */	

	function _prep_query($sql)

	{

		return $sql;

	}



	// --------------------------------------------------------------------



	/**

	 * Begin Transaction

	 *

	 * @access	public

	 * @return	bool		

	 */	

	function trans_begin($test_mode = FALSE)

	{

		if ( ! $this->trans_enabled)

		{

			return TRUE;

		}

		

		// When transactions are nested we only begin/commit/rollback the outermost ones

		if ($this->_trans_depth > 0)

		{

			return TRUE;

		}



		// Reset the transaction failure flag.

		// If the $test_mode flag is set to TRUE transactions will be rolled back

		// even if the queries produce a successful result.

		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;



		return @pg_exec($this->conn_id, "begin");

	}



	// --------------------------------------------------------------------



	/**

	 * Commit Transaction

	 *

	 * @access	public

	 * @return	bool		

	 */	

	function trans_commit()

	{

		if ( ! $this->trans_enabled)

		{

			return TRUE;

		}



		// When transactions are nested we only begin/commit/rollback the outermost ones

		if ($this->_trans_depth > 0)

		{

			return TRUE;

		}



		return @pg_exec($this->conn_id, "commit");

	}



	// --------------------------------------------------------------------



	/**

	 * Rollback Transaction

	 *

	 * @access	public

	 * @return	bool		

	 */	

	function trans_rollback()

	{

		if ( ! $this->trans_enabled)

		{

			return TRUE;

		}



		// When transactions are nested we only begin/commit/rollback the outermost ones

		if ($this->_trans_depth > 0)

		{

			return TRUE;

		}



		return @pg_exec($this->conn_id, "rollback");

	}



	// --------------------------------------------------------------------



	/**

	 * Escape String

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function escape_str($str)	

	{	

		return pg_escape_string($str);

	}

		

	// --------------------------------------------------------------------



	/**

	 * Affected Rows

	 *

	 * @access	public

	 * @return	integer

	 */

	function affected_rows()

	{

		return @pg_affected_rows($this->result_id);

	}

	

	// --------------------------------------------------------------------



	/**

	 * Insert ID

	 *

	 * @access	public

	 * @return	integer

	 */

	function insert_id()

	{

		$v = $this->_version();

		$v = $v['server'];

		

		$table	= func_num_args() > 0 ? func_get_arg(0) : null;

		$column	= func_num_args() > 1 ? func_get_arg(1) : null;

		

		if ($table == null && $v >= '8.1')

		{

			$sql='SELECT LASTVAL() as ins_id';

		}

		elseif ($table != null && $column != null && $v >= '8.0')

		{

			$sql = sprintf("SELECT pg_get_serial_sequence('%s','%s') as seq", $table, $column);

			$query = $this->query($sql);

			$row = $query->row();

			$sql = sprintf("SELECT CURRVAL('%s') as ins_id", $row->seq);

		}

		elseif ($table != null)

		{

			// seq_name passed in table parameter

			$sql = sprintf("SELECT CURRVAL('%s') as ins_id", $table);

		}

		else

		{

			return pg_last_oid($this->result_id);

		}

		$query = $this->query($sql);

		$row = $query->row();

		return $row->ins_id;

	}



	// --------------------------------------------------------------------



	/**

	 * "Count All" query

	 *

	 * Generates a platform-specific query string that counts all records in

	 * the specified database

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function count_all($table = '')

	{

		if ($table == '')

			return '0';



		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows'). " FROM " . $this->_protect_identifiers($this->dbprefix.$table));

				

		if ($query->num_rows() == 0)

			return '0';



		$row = $query->row();

		return $row->numrows;

	}



	// --------------------------------------------------------------------



	/**

	 * Show table query

	 *

	 * Generates a platform-specific query string so that the table names can be fetched

	 *

	 * @access	private

	 * @param	boolean

	 * @return	string

	 */

	function _list_tables($prefix_limit = FALSE)

	{	

		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'";	

		

		if ($prefix_limit !== FALSE AND $this->dbprefix != '')

		{

			$sql .= " AND table_name LIKE '".$this->dbprefix."%'";

		}

		

		return $sql;

	}

	

	// --------------------------------------------------------------------



	/**

	 * Show column query

	 *

	 * Generates a platform-specific query string so that the column names can be fetched

	 *

	 * @access	public

	 * @param	string	the table name

	 * @return	string

	 */

	function _list_columns($table = '')

	{

		return "SELECT column_name FROM information_schema.columns WHERE table_name ='".$this->_escape_table($table)."'";

	}



	// --------------------------------------------------------------------



	/**

	 * Field data query

	 *

	 * Generates a platform-specific query so that the column data can be retrieved

	 *

	 * @access	public

	 * @param	string	the table name

	 * @return	object

	 */

	function _field_data($table)

	{

		return "SELECT * FROM ".$this->_escape_table($table)." LIMIT 1";

	}



	// --------------------------------------------------------------------



	/**

	 * The error message string

	 *

	 * @access	private

	 * @return	string

	 */

	function _error_message()

	{

		return pg_last_error($this->conn_id);

	}

	

	// --------------------------------------------------------------------



	/**

	 * The error message number

	 *

	 * @access	private

	 * @return	integer

	 */

	function _error_number()

	{

		return '';

	}

	

	// --------------------------------------------------------------------



	/**

	 * Escape Table Name

	 *

	 * This function adds backticks if the table name has a period

	 * in it. Some DBs will get cranky unless periods are escaped.

	 *

	 * @access	private

	 * @param	string	the table name

	 * @return	string

	 */

	function _escape_table($table)

	{

		if (stristr($table, '.'))

		{

			$table = '"'.preg_replace("/\./", '"."', $table).'"';

		}

		

		return $table;

	}

	

	// --------------------------------------------------------------------



	/**

	 * Protect Identifiers

	 *

	 * This function adds backticks if appropriate based on db type

	 *

	 * @access	private

	 * @param	mixed	the item to escape

	 * @param	boolean	only affect the first word

	 * @return	mixed	the item with backticks

	 */

	function _protect_identifiers($item, $first_word_only = FALSE)

	{

		if (is_array($item))

		{

			$escaped_array = array();



			foreach($item as $k=>$v)

			{

				$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v, $first_word_only);

			}



			return $escaped_array;

		}	



		// This function may get "item1 item2" as a string, and so

		// we may need ""item1" "item2"" and not ""item1 item2""

		if (ctype_alnum($item) === FALSE)

		{

			// This function may get "field >= 1", and need it to return ""field" >= 1"

			$lbound = ($first_word_only === TRUE) ? '' : '|\s|\(';



			$item = preg_replace('/(^'.$lbound.')([\w\d\-\_]+?)(\s|\)|$)/iS', '$1"$2"$3', $item);

		}

		else

		{

			return "\"{$item}\"";

		}



		$exceptions = array('AS', '/', '-', '%', '+', '*');

		

		foreach ($exceptions as $exception)

		{

		

			if (stristr($item, " \"{$exception}\" ") !== FALSE)

			{

				$item = preg_replace('/ "('.preg_quote($exception).')" /i', ' $1 ', $item);

			}

		}

		return $item;

	}

			

	// --------------------------------------------------------------------



	/**

	 * From Tables

	 *

	 * This function implicitly groups FROM tables so there is no confusion

	 * about operator precedence in harmony with SQL standards

	 *

	 * @access	public

	 * @param	type

	 * @return	type

	 */

	function _from_tables($tables)

	{

		if (! is_array($tables))

		{

			$tables = array($tables);

		}

		

		return '('.implode(', ', $tables).')';

	}



	// --------------------------------------------------------------------

	

	/**

	 * Insert statement

	 *

	 * Generates a platform-specific insert string from the supplied data

	 *

	 * @access	public

	 * @param	string	the table name

	 * @param	array	the insert keys

	 * @param	array	the insert values

	 * @return	string

	 */

	function _insert($table, $keys, $values)

	{	

		return "INSERT INTO ".$this->_escape_table($table)." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";

	}

	

	// --------------------------------------------------------------------



	/**

	 * Update statement

	 *

	 * Generates a platform-specific update string from the supplied data

	 *

	 * @access	public

	 * @param	string	the table name

	 * @param	array	the update data

	 * @param	array	the where clause

	 * @param	array	the orderby clause

	 * @param	array	the limit clause

	 * @return	string

	 */

	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)

	{

		foreach($values as $key => $val)

		{

			$valstr[] = $key." = ".$val;

		}

		

		$limit = (!$limit) ? '' : ' LIMIT '.$limit;

		

		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';

	

		return "UPDATE ".$this->_escape_table($table)." SET ".implode(', ', $valstr)." WHERE ".implode(" ", $where).$orderby.$limit;

	}



	

	// --------------------------------------------------------------------



	/**

	 * Truncate statement

	 *

	 * Generates a platform-specific truncate string from the supplied data

	 * If the database does not support the truncate() command

	 * This function maps to "DELETE FROM table"

	 *

	 * @access	public

	 * @param	string	the table name

	 * @return	string

	 */	

	function _truncate($table)

	{

		return "TRUNCATE ".$this->_escape_table($table);

	}

	

	// --------------------------------------------------------------------



	/**

	 * Delete statement

	 *

	 * Generates a platform-specific delete string from the supplied data

	 *

	 * @access	public

	 * @param	string	the table name

	 * @param	array	the where clause

	 * @param	string	the limit clause

	 * @return	string

	 */	

	function _delete($table, $where = array(), $like = array(), $limit = FALSE)

	{

		$conditions = '';



		if (count($where) > 0 || count($like) > 0)

		{

			$conditions = "\nWHERE ";

			$conditions .= implode("\n", $this->ar_where);



			if (count($where) > 0 && count($like) > 0)

			{

				$conditions .= " AND ";

			}

			$conditions .= implode("\n", $like);

		}



		$limit = (!$limit) ? '' : ' LIMIT '.$limit;

	

		return "DELETE FROM ".$table.$conditions.$limit;

	}



	// --------------------------------------------------------------------

	/**

	 * Limit string

	 *

	 * Generates a platform-specific LIMIT clause

	 *

	 * @access	public

	 * @param	string	the sql query string

	 * @param	integer	the number of rows to limit the query to

	 * @param	integer	the offset value

	 * @return	string

	 */

	function _limit($sql, $limit, $offset)

	{	

		$sql .= "LIMIT ".$limit;

	

		if ($offset > 0)

		{

			$sql .= " OFFSET ".$offset;

		}

		

		return $sql;

	}



	// --------------------------------------------------------------------



	/**

	 * Close DB Connection

	 *

	 * @access	public

	 * @param	resource

	 * @return	void

	 */

	function _close($conn_id)

	{

		@pg_close($conn_id);

	}





}



?>