mysql存储过程之返回多个值的方法示例

吾爱主题阅读：110 2024-04-05 16:19:26 评论：0

本文实例讲述了mysql 存储过程之返回多个值的方法。分享给大家供大家参考，具体如下：

mysql存储函数只返回一个值。要开发返回多个值的存储过程，需要使用带有INOUT或OUT参数的存储过程。咱们先来看一个orders表它的结构：

1 2 3 4 5 6 7 8 9 10 11 12 13 mysql> desc orders; + ----------------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | + ----------------+-------------+------+-----+---------+-------+ | orderNumber | int (11) | NO | PRI | NULL | | | orderDate | date | NO | | NULL | | | requiredDate | date | NO | | NULL | | | shippedDate | date | YES | | NULL | | | status | varchar (15) | NO | | NULL | | | comments | text | YES | | NULL | | | customerNumber | int (11) | NO | MUL | NULL | | + ----------------+-------------+------+-----+---------+-------+ 7 rows in set

然后嘞，咱们来看一个存储过程，它接受客户编号，并返回发货(shipped)，取消(canceled)，解决(resolved)和争议(disputed)的订单总数：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 DELIMITER $$ CREATE PROCEDURE get_order_by_cust( IN cust_no INT , OUT shipped INT , OUT canceled INT , OUT resolved INT , OUT disputed INT ) BEGIN -- shipped SELECT count (*) INTO shipped FROM orders WHERE customerNumber = cust_no AND status = 'Shipped' ; -- canceled SELECT count (*) INTO canceled FROM orders WHERE customerNumber = cust_no AND status = 'Canceled' ; -- resolved SELECT count (*) INTO resolved FROM orders WHERE customerNumber = cust_no AND status = 'Resolved' ; -- disputed SELECT count (*) INTO disputed FROM orders WHERE customerNumber = cust_no AND status = 'Disputed' ; END

其实，除IN参数之外，存储过程还需要4个额外的OUT参数：shipped, canceled, resolved 和 disputed。在存储过程中，使用带有count函数的select语句根据订单状态获取相应的订单总数，并将其分配给相应的参数。按着上面的sql，我们如果要使用get_order_by_cust存储过程，可以传递客户编号和四个用户定义的变量来获取输出值。执行存储过程后，我们再使用SELECT语句输出变量值：

1 2 3 4 5 6 + ----------+-----------+-----------+-----------+ | @shipped | @canceled | @resolved | @disputed | + ----------+-----------+-----------+-----------+ | 22 | 0 | 1 | 1 | + ----------+-----------+-----------+-----------+ 1 row in set

结合实际应用，我们再来看下从PHP程序中调用返回多个值的存储过程：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 <?php /** * Call stored procedure that return multiple values * @param $customerNumber */ function call_sp( $customerNumber ) { try { $pdo = new PDO( "mysql:host=localhost;dbname=yiibaidb" , 'root' , '123456' ); // execute the stored procedure $sql = 'CALL get_order_by_cust(:no,@shipped,@canceled,@resolved,@disputed)' ; $stmt = $pdo ->prepare( $sql ); $stmt ->bindParam( ':no' , $customerNumber , PDO::PARAM_INT); $stmt ->execute(); $stmt ->closeCursor(); // execute the second query to get values from OUT parameter $r = $pdo ->query( "SELECT @shipped,@canceled,@resolved,@disputed" ) ->fetch(PDO::FETCH_ASSOC); if ( $r ) { printf( 'Shipped: %d, Canceled: %d, Resolved: %d, Disputed: %d' , $r [ '@shipped' ], $r [ '@canceled' ], $r [ '@resolved' ], $r [ '@disputed' ]); } } catch (PDOException $pe ) { die ( "Error occurred:" . $pe ->getMessage()); } } call_sp(141);