/system/database/drivers/mysqli/mysqli_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

 */



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



/**

 * MySQLi Database Adapter Class - MySQLi only works with PHP 5

 *

 * 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_mysqli_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 = ' RAND()'; // database specific random keyword



	/**

	 * Whether to use the MySQL "delete hack" which allows the number

	 * of affected rows to be shown. Uses a preg_replace when enabled,

	 * adding a bit more processing to all queries.

	 */	

	var $delete_hack = TRUE;



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



	/**

	 * Non-persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_connect()

	{

		return @mysqli_connect($this->hostname, $this->username, $this->password);

	}



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



	/**

	 * Persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_pconnect()

	{

		return $this->db_connect();

	}

	

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



	/**

	 * Select the database

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */	

	function db_select()

	{

		return @mysqli_select_db($this->conn_id, $this->database);

	}



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



	/**

	 * 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);	

		$result = @mysqli_query($this->conn_id, $sql);

		return $result;

	}

	

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



	/**

	 * 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)

	{

		// "DELETE FROM TABLE" returns 0 affected rows This hack modifies

		// the query so that it returns the number of affected rows

		if ($this->delete_hack === TRUE)

		{

			if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))

			{

				$sql = preg_replace("/^\s*DELETE\s+FROM\s+(\S+)\s*$/", "DELETE FROM \\1 WHERE 1=1", $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;



		$this->simple_query('SET AUTOCOMMIT=0');

		$this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK

		return TRUE;

	}



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



	/**

	 * 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;

		}



		$this->simple_query('COMMIT');

		$this->simple_query('SET AUTOCOMMIT=1');

		return TRUE;

	}



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



	/**

	 * 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;

		}



		$this->simple_query('ROLLBACK');

		$this->simple_query('SET AUTOCOMMIT=1');

		return TRUE;

	}



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



	/**

	 * Escape String

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function escape_str($str)	

	{

		if (function_exists('mysqli_real_escape_string') AND is_resource($this->conn_id))

		{

			return mysqli_real_escape_string($this->conn_id, $str);

		}

		elseif (function_exists('mysql_escape_string'))

		{

			return mysql_escape_string($str);

		}

		else

		{

			return addslashes($str);

		}

	}

		

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



	/**

	 * Affected Rows

	 *

	 * @access	public

	 * @return	integer

	 */

	function affected_rows()

	{

		return @mysqli_affected_rows($this->conn_id);

	}

	

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



	/**

	 * Insert ID

	 *

	 * @access	public

	 * @return	integer

	 */

	function insert_id()

	{

		return @mysqli_insert_id($this->conn_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;

	}



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



	/**

	 * List 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)

	{

		$sql = "SHOW TABLES FROM `".$this->database."`";	

		

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

		{

			$sql .= " LIKE '".$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 "SHOW COLUMNS FROM ".$this->_escape_table($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 mysqli_error($this->conn_id);

	}

	

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



	/**

	 * The error message number

	 *

	 * @access	private

	 * @return	integer

	 */

	function _error_number()

	{

		return mysqli_errno($this->conn_id);

	}

	

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



	/**

	 * 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)

	{

		@mysqli_close($conn_id);

	}





}



?>