1: <?php
 2: /**
 3:  * CMysqlCommandBuilder class file.
 4:  *
 5:  * @author Carsten Brandt <mail@cebe.cc>
 6:  * @link http://www.yiiframework.com/
 7:  * @copyright 2008-2013 Yii Software LLC
 8:  * @license http://www.yiiframework.com/license/
 9:  */
10: 
11: /**
12:  * CMysqlCommandBuilder provides basic methods to create query commands for tables.
13:  *
14:  * @author Carsten Brandt <mail@cebe.cc>
15:  * @package system.db.schema.mysql
16:  * @since 1.1.13
17:  */
18: class CMysqlCommandBuilder extends CDbCommandBuilder
19: {
20:     /**
21:      * Alters the SQL to apply JOIN clause.
22:      * This method handles the mysql specific syntax where JOIN has to come before SET in UPDATE statement
23:      * and for DELETE where JOIN has to be after FROM part.
24:      * @param string $sql the SQL statement to be altered
25:      * @param string $join the JOIN clause (starting with join type, such as INNER JOIN)
26:      * @return string the altered SQL statement
27:      */
28:     public function applyJoin($sql,$join)
29:     {
30:         if($join=='')
31:             return $sql;
32: 
33:         if(strpos($sql,'UPDATE')===0 && ($pos=strpos($sql,'SET'))!==false)
34:             return substr($sql,0,$pos).$join.' '.substr($sql,$pos);
35:         elseif(strpos($sql,'DELETE FROM ')===0)
36:         {
37:             $tableName=substr($sql,12);
38:             return "DELETE {$tableName} FROM {$tableName} ".$join;
39:         }
40:         else
41:             return $sql.' '.$join;
42:     }
43: 
44:     /**
45:      * Alters the SQL to apply LIMIT and OFFSET.
46:      * @param string $sql SQL query string without LIMIT and OFFSET.
47:      * @param integer $limit maximum number of rows, -1 to ignore limit.
48:      * @param integer $offset row offset, -1 to ignore offset.
49:      * @return string SQL with LIMIT and OFFSET
50:      */
51:     public function applyLimit($sql,$limit,$offset)
52:     {
53:         // Ugly, but this is how MySQL recommends doing it: https://dev.mysql.com/doc/refman/5.0/en/select.html
54:         if($limit<=0 && $offset>0)
55:             $limit=PHP_INT_MAX;
56:         return parent::applyLimit($sql,$limit,$offset);
57:     }
58: }
59: