Improve the PostgreSQL database driver

1 files changed, 168 insertions, 189 deletions

diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 42329bded..8b8f33371 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -25,8 +25,6 @@
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * Postgre Database Adapter Class
  *
@@ -42,47 +40,56 @@
  */
 class CI_DB_postgre_driver extends CI_DB {
 
-	var $dbdriver = 'postgre';
+	public $dbdriver = 'postgre';
 
-	var $_escape_char = '"';
+	protected $_escape_char = '"';
 
 	// clause and character used for LIKE escape sequences
-	var $_like_escape_str = " ESCAPE '%s' ";
-	var $_like_escape_chr = '!';
+	protected $_like_escape_str = ' ESCAPE \'%s\' ';
+	protected $_like_escape_chr = '!';
 
 	/**
 	 * 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
+	protected $_count_string = 'SELECT COUNT(*) AS ';
+	protected $_random_keyword = ' RANDOM()'; // database specific random keyword
+
+	// Postgre-specific properties
+	protected $_pg_dsn;
 
 	/**
-	 * Connection String
+	 * Constructor
 	 *
-	 * @access	private
-	 * @return	string
+	 * Creates a DSN string to be used for db_connect() and db_pconnect()
+	 *
+	 * @return	void
 	 */
-	function _connect_string()
+	private function __construct($params)
 	{
+		parent::__construct($params);
+
 		$components = array(
-								'hostname'	=> 'host',
-								'port'		=> 'port',
-								'database'	=> 'dbname',
-								'username'	=> 'user',
-								'password'	=> 'password'
-							);
-
-		$connect_string = "";
+					'hostname'	=> 'host',
+					'port'		=> 'port',
+					'database'	=> 'dbname',
+					'username'	=> 'user',
+					'password'	=> 'password'
+				);
+
 		foreach ($components as $key => $val)
 		{
 			if (isset($this->$key) && $this->$key != '')
 			{
-				$connect_string .= " $val=".$this->$key;
+				$this->_pg_dsn .= $val.'='.$this->$key.' ';
 			}
 		}
-		return trim($connect_string);
+
+		if (strlen($this->_pg_dsn) > 0)
+		{
+			$this->_pg_dsn = rtrim($this->_pg_dsn);
+		}
 	}
 
 	// --------------------------------------------------------------------
@@ -90,12 +97,17 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_connect()
+	public function db_connect()
 	{
-		return @pg_connect($this->_connect_string());
+		$ret = @pg_connect($this->_pg_dsn);
+		if (is_resource($ret) && $this->char_set != '')
+		{
+			pg_set_client_encoding($ret, $this->char_set);
+		}
+
+		return $ret;
 	}
 
 	// --------------------------------------------------------------------
@@ -103,12 +115,17 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Persistent database connection
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_pconnect()
+	public function db_pconnect()
 	{
-		return @pg_pconnect($this->_connect_string());
+		$ret = @pg_pconnect($this->_pg_dsn);
+		if (is_resource($ret) && $this->char_set != '')
+		{
+			pg_set_client_encoding($ret, $this->char_set);
+		}
+
+		return $ret;
 	}
 
 	// --------------------------------------------------------------------
@@ -119,10 +136,9 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Keep / reestablish the db connection if no queries have been
 	 * sent for a length of time exceeding the server's idle timeout
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function reconnect()
+	public function reconnect()
 	{
 		if (pg_ping($this->conn_id) === FALSE)
 		{
@@ -135,10 +151,9 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_select()
+	public function db_select()
 	{
 		// Not needed for Postgre so we'll return TRUE
 		return TRUE;
@@ -149,15 +164,35 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Set client character set
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	string
-	 * @return	resource
+	 * @return	bool
 	 */
-	function db_set_charset($charset, $collation)
+	public function db_set_charset($charset, $collation)
 	{
-		// @todo - add support if needed
-		return TRUE;
+		return (pg_set_client_encoding($this->conn_id, $charset) === 0);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Database version
+	 *
+	 * This method overrides the one from the base class, as if PHP was
+	 * compiled with PostgreSQL version >= 7.4 libraries, we have a native
+	 * function to get the server's version.
+	 *
+	 * @return	string
+	 */
+
+	public function version()
+	{
+		$version = pg_version($this->conn_id);
+
+		/* If we don't have the server version string - fall back to
+		 * the base driver class' method
+		 */
+		return isset($version['server']) ? $version['server'] : parent::version();
 	}
 
 	// --------------------------------------------------------------------
@@ -165,12 +200,11 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Version number query string
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function _version()
+	protected function _version()
 	{
-		return "SELECT version() AS ver";
+		return 'SELECT version() AS ver';
 	}
 
 	// --------------------------------------------------------------------
@@ -178,14 +212,12 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @access	private called by the base class
 	 * @param	string	an SQL query
 	 * @return	resource
 	 */
-	function _execute($sql)
+	protected function _execute($sql)
 	{
-		$sql = $this->_prep_query($sql);
-		return @pg_query($this->conn_id, $sql);
+		return @pg_query($this->conn_id, $this->_prep_query($sql));
 	}
 
 	// --------------------------------------------------------------------
@@ -195,11 +227,10 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * 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($sql)
+	protected function _prep_query($sql)
 	{
 		return $sql;
 	}
@@ -209,18 +240,13 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Begin Transaction
 	 *
-	 * @access	public
+	 * @param	bool
 	 * @return	bool
 	 */
-	function trans_begin($test_mode = FALSE)
+	public 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)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -228,9 +254,9 @@ class CI_DB_postgre_driver extends CI_DB {
 		// 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;
+		$this->_trans_failure = ($test_mode === TRUE);
 
-		return @pg_exec($this->conn_id, "begin");
+		return (bool) @pg_query($this->conn_id, 'BEGIN');
 	}
 
 	// --------------------------------------------------------------------
@@ -238,23 +264,17 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Commit Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_commit()
+	public 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)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		return @pg_exec($this->conn_id, "commit");
+		return (bool) @pg_query($this->conn_id, 'COMMIT');
 	}
 
 	// --------------------------------------------------------------------
@@ -262,23 +282,17 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Rollback Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_rollback()
+	public 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)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		return @pg_exec($this->conn_id, "rollback");
+		return (bool) @pg_query($this->conn_id, 'ROLLBACK');
 	}
 
 	// --------------------------------------------------------------------
@@ -286,12 +300,11 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Escape String
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	bool	whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
-	function escape_str($str, $like = FALSE)
+	public function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
@@ -308,9 +321,9 @@ class CI_DB_postgre_driver extends CI_DB {
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(	array('%', '_', $this->_like_escape_chr),
-								array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
-								$str);
+			return str_replace(array('%', '_', $this->_like_escape_chr),
+						array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
+						$str);
 		}
 
 		return $str;
@@ -321,10 +334,9 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Affected Rows
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function affected_rows()
+	public function affected_rows()
 	{
 		return @pg_affected_rows($this->result_id);
 	}
@@ -334,40 +346,45 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Insert ID
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function insert_id()
+	public function insert_id()
 	{
-		$v = $this->_version();
-		$v = $v['server'];
+		$v = pg_version($this->conn_id);
+		$v = isset($v['server']) ? $v['server'] : 0; // 'server' key is only available since PosgreSQL 7.4
 
-		$table	= func_num_args() > 0 ? func_get_arg(0) : NULL;
-		$column	= func_num_args() > 1 ? func_get_arg(1) : NULL;
+		$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);
+			$sql = 'SELECT LASTVAL() AS ins_id';
 		}
 		elseif ($table != NULL)
 		{
-			// seq_name passed in table parameter
-			$sql = sprintf("SELECT CURRVAL('%s') as ins_id", $table);
+			if ($column != NULL && $v >= '8.0')
+			{
+				$sql = 'SELECT pg_get_serial_sequence(\''.$table."', '".$column."') AS seq";
+				$query = $this->query($sql);
+				$query = $query->row();
+				$seq = $query->seq;
+			}
+			else
+			{
+				// seq_name passed in table parameter
+				$seq = $table;
+			}
+
+			$sql = 'SELECT CURRVAL(\''.$seq."') AS ins_id";
 		}
 		else
 		{
 			return pg_last_oid($this->result_id);
 		}
+
 		$query = $this->query($sql);
-		$row = $query->row();
-		return $row->ins_id;
+		$query = $query->row();
+		return (int) $query->ins_id;
 	}
 
 	// --------------------------------------------------------------------
@@ -378,27 +395,25 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Generates a platform-specific query string that counts all records in
 	 * the specified database
 	 *
-	 * @access	public
 	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	public function count_all($table = '')
 	{
 		if ($table == '')
 		{
 			return 0;
 		}
 
-		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
-
+		$query = $this->query($this->_count_string.$this->_protect_identifiers('numrows').' FROM '.$this->_protect_identifiers($table, TRUE, NULL, FALSE));
 		if ($query->num_rows() == 0)
 		{
 			return 0;
 		}
 
-		$row = $query->row();
+		$query = $query->row();
 		$this->_reset_select();
-		return (int) $row->numrows;
+		return (int) $query->numrows;
 	}
 
 	// --------------------------------------------------------------------
@@ -408,17 +423,16 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
-	 * @param	boolean
+	 * @param	bool
 	 * @return	string
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
 		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'";
 
-		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		if ($prefix_limit !== FALSE && $this->dbprefix != '')
 		{
-			$sql .= " AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -431,13 +445,12 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
-		return "SELECT column_name FROM information_schema.columns WHERE table_name ='".$table."'";
+		return "SELECT column_name FROM information_schema.columns WHERE table_name = '".$table."'";
 	}
 
 	// --------------------------------------------------------------------
@@ -447,13 +460,12 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	string
 	 */
-	function _field_data($table)
+	protected function _field_data($table)
 	{
-		return "SELECT * FROM ".$table." LIMIT 1";
+		return 'SELECT * FROM '.$table.' LIMIT 1';
 	}
 
 	// --------------------------------------------------------------------
@@ -461,10 +473,9 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * The error message string
 	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _error_message()
+	protected function _error_message()
 	{
 		return pg_last_error($this->conn_id);
 	}
@@ -474,11 +485,11 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * The error message number
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @return	string
 	 */
-	function _error_number()
+	protected function _error_number()
 	{
+		// Not supported in Postgre
 		return '';
 	}
 
@@ -489,11 +500,10 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * This function escapes column and table names
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	string
 	 */
-	function _escape_identifiers($item)
+	public function _escape_identifiers($item)
 	{
 		if ($this->_escape_char == '')
 		{
@@ -504,24 +514,20 @@ class CI_DB_postgre_driver extends CI_DB {
 		{
 			if (strpos($item, '.'.$id) !== FALSE)
 			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
+				$item = str_replace('.', $this->_escape_char.'.', $item);
 
 				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
 			}
 		}
 
 		if (strpos($item, '.') !== FALSE)
 		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
+			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
 		}
 
 		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
 	}
 
 	// --------------------------------------------------------------------
@@ -532,11 +538,10 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * 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
+	 * @param	string	table name
+	 * @return	string
 	 */
-	function _from_tables($tables)
+	protected function _from_tables($tables)
 	{
 		if ( ! is_array($tables))
 		{
@@ -553,15 +558,14 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	function _insert($table, $keys, $values)
+	protected function _insert($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -571,15 +575,14 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * 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_batch($table, $keys, $values)
+	protected function _insert_batch($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES ".implode(', ', $values);
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -589,7 +592,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * 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
@@ -597,24 +599,17 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * @param	array	the limit clause
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
 	{
 		foreach ($values as $key => $val)
 		{
-			$valstr[] = $key." = ".$val;
+			$valstr[] = $key.' = '.$val;
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
+			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
+			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
+			.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 	// --------------------------------------------------------------------
@@ -626,13 +621,12 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * 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($table)
+	protected function _truncate($table)
 	{
-		return "TRUNCATE ".$table;
+		return 'TRUNCATE '.$table;
 	}
 
 	// --------------------------------------------------------------------
@@ -642,31 +636,27 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * 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(), $limit = FALSE)
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';
 
 		if (count($where) > 0 OR count($like) > 0)
 		{
-			$conditions = "\nWHERE ";
-			$conditions .= implode("\n", $this->ar_where);
+			$conditions = "\nWHERE ".implode("\n", $this->ar_where);
 
 			if (count($where) > 0 && count($like) > 0)
 			{
-				$conditions .= " AND ";
+				$conditions .= ' AND ';
 			}
 			$conditions .= implode("\n", $like);
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		return "DELETE FROM ".$table.$conditions.$limit;
+		return 'DELETE FROM '.$table.$conditions.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 	// --------------------------------------------------------------------
@@ -675,22 +665,14 @@ class CI_DB_postgre_driver extends CI_DB {
 	 *
 	 * 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
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _limit($sql, $limit, $offset)
 	{
-		$sql .= "LIMIT ".$limit;
-
-		if ($offset > 0)
-		{
-			$sql .= " OFFSET ".$offset;
-		}
-
-		return $sql;
+		return $sql.' LIMIT '.$limit.($offset == 0 ? '' : ' OFFSET '.$offset);
 	}
 
 	// --------------------------------------------------------------------
@@ -698,18 +680,15 @@ class CI_DB_postgre_driver extends CI_DB {
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
 	 * @param	resource
 	 * @return	void
 	 */
-	function _close($conn_id)
+	protected function _close($conn_id)
 	{
 		@pg_close($conn_id);
 	}
 
-
 }
 
-
 /* End of file postgre_driver.php */
-/* Location: ./system/database/drivers/postgre/postgre_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/postgre/postgre_driver.php */