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 5.2.4 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:
 * http://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @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 query builder
 * class is being used or not.
 *
 * @package		CodeIgniter
 * @subpackage	Drivers
 * @category	Database
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_postgre_driver extends CI_DB {

	public $dbdriver = 'postgre';

	protected $_escape_char = '"';

	// clause and character used for LIKE escape sequences
	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.
	 */
	protected $_count_string = 'SELECT COUNT(*) AS ';
	protected $_random_keyword = ' RANDOM()'; // database specific random keyword

	/**
	 * Constructor
	 *
	 * Creates a DSN string to be used for db_connect() and db_pconnect()
	 *
	 * @return	void
	 */
	public function __construct($params)
	{
		parent::__construct($params);

		if ( ! empty($this->dsn))
		{
			return;
		}

		$this->dsn === '' OR $this->dsn = '';

		if (strpos($this->hostname, '/') !== FALSE)
		{
			// If UNIX sockets are used, we shouldn't set a port
			$this->port = '';
		}

		$this->hostname === '' OR $this->dsn = 'host='.$this->hostname.' ';

		if ( ! empty($this->port) && ctype_digit($this->port))
		{
			$this->dsn .= 'port='.$this->port.' ';
		}

		if ($this->username !== '')
		{
			$this->dsn .= 'user='.$this->username.' ';

			/* An empty password is valid!
			 *
			 * $db['password'] = NULL must be done in order to ignore it.
			 */
			$this->password === NULL OR $this->dsn .= "password='".$this->password."' ";
		}

		$this->database === '' OR $this->dsn .= 'dbname='.$this->database.' ';

		/* We don't have these options as elements in our standard configuration
		 * array, but they might be set by parse_url() if the configuration was
		 * provided via string. Example:
		 *
		 * postgre://username:password@localhost:5432/database?connect_timeout=5&sslmode=1
		 */
		foreach (array('connect_timeout', 'options', 'sslmode', 'service') as $key)
		{
			if (isset($this->$key) && is_string($this->key) && $this->key !== '')
			{
				$this->dsn .= $key."='".$this->key."' ";
			}
		}

		$this->dsn = rtrim($this->dsn);
	}

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

	/**
	 * Non-persistent database connection
	 *
	 * @return	resource
	 */
	public function db_connect()
	{
		return @pg_connect($this->dsn);
	}

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

	/**
	 * Persistent database connection
	 *
	 * @return	resource
	 */
	public function db_pconnect()
	{
		return @pg_pconnect($this->dsn);
	}

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

	/**
	 * Reconnect
	 *
	 * Keep / reestablish the db connection if no queries have been
	 * sent for a length of time exceeding the server's idle timeout
	 *
	 * @return	void
	 */
	public function reconnect()
	{
		if (pg_ping($this->conn_id) === FALSE)
		{
			$this->conn_id = FALSE;
		}
	}

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

	/**
	 * Set client character set
	 *
	 * @param	string
	 * @return	bool
	 */
	protected function _db_set_charset($charset)
	{
		return (pg_set_client_encoding($this->conn_id, $charset) === 0);
	}

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

	/**
	 * Database version number
	 *
	 * @return	string
	 */
	public function version()
	{
		if (isset($this->data_cache['version']))
		{
			return $this->data_cache['version'];
		}

		if (($pg_version = pg_version($this->conn_id)) === FALSE)
		{
			return FALSE;
		}

		/* If PHP was compiled with PostgreSQL lib versions earlier
		 * than 7.4, pg_version() won't return the server version
		 * and so we'll have to fall back to running a query in
		 * order to get it.
		 */
		return isset($pg_version['server'])
			? $this->data_cache['version'] = $pg_version['server']
			: parent::version();
	}

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

	/**
	 * Execute the query
	 *
	 * @param	string	an SQL query
	 * @return	resource
	 */
	protected function _execute($sql)
	{
		return @pg_query($this->conn_id, $sql);
	}

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

	/**
	 * Begin Transaction
	 *
	 * @param	bool
	 * @return	bool
	 */
	public function trans_begin($test_mode = FALSE)
	{
		// When transactions are nested we only begin/commit/rollback the outermost ones
		if ( ! $this->trans_enabled OR $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);

		return (bool) @pg_query($this->conn_id, 'BEGIN');
	}

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

	/**
	 * Commit Transaction
	 *
	 * @return	bool
	 */
	public function trans_commit()
	{
		// When transactions are nested we only begin/commit/rollback the outermost ones
		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
		{
			return TRUE;
		}

		return (bool) @pg_query($this->conn_id, 'COMMIT');
	}

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

	/**
	 * Rollback Transaction
	 *
	 * @return	bool
	 */
	public function trans_rollback()
	{
		// When transactions are nested we only begin/commit/rollback the outermost ones
		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
		{
			return TRUE;
		}

		return (bool) @pg_query($this->conn_id, 'ROLLBACK');
	}

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

	/**
	 * Escape String
	 *
	 * @param	string
	 * @param	bool	whether or not the string will be used in a LIKE condition
	 * @return	string
	 */
	public 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 ($like === TRUE)
		{
			return str_replace(array($this->_like_escape_chr, '%', '_'),
						array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
						$str);
		}

		return $str;
	}

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

	/**
	 * "Smart" Escape String
	 *
	 * Escapes data based on type
	 * Sets boolean and null types
	 *
	 * @param	string
	 * @return	mixed
	 */
	public function escape($str)
	{
		if (is_string($str) OR method_exists($str, '__toString'))
		{
			return "'".$this->escape_str($str)."'";
		}
		elseif (is_bool($str))
		{
			return ($str) ? 'TRUE' : 'FALSE';
		}
		elseif (is_null($str))
		{
			return 'NULL';
		}

		return $str;
	}
	
	// --------------------------------------------------------------------

	/**
	 * Affected Rows
	 *
	 * @return	int
	 */
	public function affected_rows()
	{
		return @pg_affected_rows($this->result_id);
	}

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

	/**
	 * Insert ID
	 *
	 * @return	string
	 */
	public function insert_id()
	{
		$v = pg_version($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;

		if ($table == NULL && $v >= '8.1')
		{
			$sql = 'SELECT LASTVAL() AS ins_id';
		}
		elseif ($table != NULL)
		{
			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);
		$query = $query->row();
		return (int) $query->ins_id;
	}

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

	/**
	 * "Count All" query
	 *
	 * Generates a platform-specific query string that counts all records in
	 * the specified database
	 *
	 * @param	string
	 * @return	string
	 */
	public function count_all($table = '')
	{
		if ($table == '')
		{
			return 0;
		}

		$query = $this->query($this->_count_string.$this->protect_identifiers('numrows').' FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE));
		if ($query->num_rows() == 0)
		{
			return 0;
		}

		$query = $query->row();
		$this->_reset_select();
		return (int) $query->numrows;
	}

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

	/**
	 * Show table query
	 *
	 * Generates a platform-specific query string so that the table names can be fetched
	 *
	 * @param	bool
	 * @return	string
	 */
	protected function _list_tables($prefix_limit = FALSE)
	{
		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'";

		if ($prefix_limit !== FALSE && $this->dbprefix != '')
		{
			return $sql." AND table_name LIKE '".$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
	 *
	 * @param	string	the table name
	 * @return	string
	 */
	protected 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
	 *
	 * @param	string	the table name
	 * @return	string
	 */
	protected function _field_data($table)
	{
		return 'SELECT * FROM '.$table.' LIMIT 1';
	}

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

	/**
	 * Error
	 *
	 * Returns an array containing code and message of the last
	 * database error that has occured.
	 *
	 * @return	array
	 */
	public function error()
	{
		return array('code' => '', 'message' => pg_last_error($this->conn_id));
	}

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

	/**
	 * From Tables
	 *
	 * This function implicitly groups FROM tables so there is no confusion
	 * about operator precedence in harmony with SQL standards
	 *
	 * @param	array
	 * @return	string
	 */
	protected function _from_tables($tables)
	{
		if ( ! is_array($tables))
		{
			$tables = array($tables);
		}

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

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

	/**
	 * Update statement
	 *
	 * Generates a platform-specific update string from the supplied data
	 *
	 * @param	string	the table name
	 * @param	array	the update data
	 * @param	array	the where clause
	 * @param	array	the orderby clause (ignored)
	 * @param	array	the limit clause (ignored)
	 * @param	array	the like clause
	 * @return	string
	 */
	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
	{
		foreach ($values as $key => $val)
		{
			$valstr[] = $key.' = '.$val;
		}

		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);

		if ( ! empty($like))
		{
			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
		}

		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where;
	}

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

	/**
	 * Delete statement
	 *
	 * Generates a platform-specific delete string from the supplied data
	 *
	 * @param	string	the table name
	 * @param	array	the where clause
	 * @param	array	the like clause
	 * @param	string	the limit clause (ignored)
	 * @return	string
	 */
	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
	{
		$conditions = array();

		empty($where) OR $conditions[] = implode(' ', $where);
		empty($like) OR $conditions[] = implode(' ', $like);

		return 'DELETE FROM '.$table.(count($conditions) > 0 ? ' WHERE '.implode(' AND ', $conditions) : '');
	}

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

	/**
	 * Limit string
	 *
	 * Generates a platform-specific LIMIT clause
	 *
	 * @param	string	the sql query string
	 * @param	int	the number of rows to limit the query to
	 * @param	int	the offset value
	 * @return	string
	 */
	protected function _limit($sql, $limit, $offset)
	{
		return $sql.' LIMIT '.$limit.($offset == 0 ? '' : ' OFFSET '.$offset);
	}

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

	/**
	 * Where
	 *
	 * Called by where() or or_where()
	 *
	 * @param	mixed
	 * @param	mixed
	 * @param	string
	 * @return	object
	 *
	 */
	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
	{
		$type = $this->_group_get_type($type);

		if ( ! is_array($key))
		{
			$key = array($key => $value);
		}

		// If the escape value was not set will will base it on the global setting
		if ( ! is_bool($escape))
		{
			$escape = $this->_protect_identifiers;
		}

		foreach ($key as $k => $v)
		{
			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;

			if (is_null($v) && ! $this->_has_operator($k))
			{
				// value appears not to have been set, assign the test to IS NULL
				$k .= ' IS NULL';
			}

			if ( ! is_null($v))
			{
				if ($escape === TRUE)
				{
					$k = $this->protect_identifiers($k, FALSE, $escape);
					$v = ' '.$this->escape($v);
				}
				elseif (is_bool($v))
				{
					$v = ' '.($v ? 'TRUE' : 'FALSE');
				}

				if ( ! $this->_has_operator($k))
				{
					$k .= ' = ';
				}
			}
			else
			{
				$k = $this->protect_identifiers($k, FALSE, $escape);
			}

			$this->qb_where[] = $prefix.$k.$v;
			if ($this->qb_caching === TRUE)
			{
				$this->qb_cache_where[] = $prefix.$k.$v;
				$this->qb_cache_exists[] = 'where';
			}

		}

		return $this;
	}
	
	// --------------------------------------------------------------------

	/**
	 * Close DB Connection
	 *
	 * @param	resource
	 * @return	void
	 */
	protected function _close($conn_id)
	{
		@pg_close($conn_id);
	}

}

/* End of file postgre_driver.php */
/* Location: ./system/database/drivers/postgre/postgre_driver.php */