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

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 5.1.6 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2008 - 2011, 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 {



	var $dbdriver = 'postgre';



	var $_escape_char = '"';



	// clause and character used for LIKE escape sequences

	var $_like_escape_str = " ESCAPE '%s' ";

	var $_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



	/**

	 * Connection String

	 *

	 * @access	private

	 * @return	string

	 */

	function _connect_string()

	{

		$components = array(

								'hostname'	=> 'host',

								'port'		=> 'port',

								'database'	=> 'dbname',

								'username'	=> 'user',

								'password'	=> 'password'

							);



		$connect_string = "";

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

		{

			if (isset($this->$key) && $this->$key != '')

			{

				$connect_string .= " $val=".$this->$key;

			}

		}

		return trim($connect_string);

	}



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



	/**

	 * Non-persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */

	function db_connect()

	{

		return @pg_connect($this->_connect_string());

	}



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



	/**

	 * Persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */

	function db_pconnect()

	{

		return @pg_pconnect($this->_connect_string());

	}



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



	/**

	 * Reconnect

	 *

	 * 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()

	{

		if (pg_ping($this->conn_id) === FALSE)

		{

			$this->conn_id = FALSE;

		}

	}



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



	/**

	 * 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

	 * @param	bool	whether or not the string will be used in a LIKE condition

	 * @return	string

	 */

	function escape_str($str, $like = FALSE)

	{

		if (is_array($str))

		{

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

			{

				$str[$key] = $this->escape_str($val, $like);

			}



			return $str;

		}



		$str = pg_escape_string($str);



		// 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;

	}



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



	/**

	 * 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 " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));



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

		{

			return 0;

		}



		$row = $query->row();

		return (int) $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->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);

		}



		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 ='".$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 ".$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 the SQL Identifiers

	 *

	 * This function escapes column and table names

	 *

	 * @access	private

	 * @param	string

	 * @return	string

	 */

	function _escape_identifiers($item)

	{

		if ($this->_escape_char == '')

		{

			return $item;

		}



		foreach ($this->_reserved_identifiers as $id)

		{

			if (strpos($item, '.'.$id) !== FALSE)

			{

				$str = $this->_escape_char. 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);

			}

		}



		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;

		}



		// remove duplicates if the user already included the escape

		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);

	}



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



	/**

	 * 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 ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";

	}



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



	/**

	 * Insert_batch 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_batch($table, $keys, $values)

	{

		return "INSERT INTO ".$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):'';



		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);



		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';



		$sql .= $orderby.$limit;



		return $sql;

	}



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



	/**

	 * 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 ".$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($where) > 0 OR count($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);

	}





}





/* End of file postgre_driver.php */

/* Location: ./system/database/drivers/postgre/postgre_driver.php */