MySQL--带有out的存储过程

Posted 2021-03-07 dongyaotou

带有out 的存储过程，同样可以返回一个值，也可以返回多个值

下面分别进行介绍

案例一：根据女神名，返回对应的男神名

 1 delimiter $
 2 create PROCEDURE myp7(in beautyName VARCHAR(20),out boyName VARCHAR(20))
 3 begin 
 4         select bo.boyName into boyName
 5         from boys bo
 6         INNER JOIN beauty b on bo.id=b.boyfriend_id
 7         where b.name=beautyName;
 8 end $
 9 #调用
10 #set @bName$  #其实这个定义用户变量过程是不用写的，直接按照下面调用的写法就行
11 call myp7(\'小昭\',@bName)$
12 select @bName$

这里我要强调一点就是，在使用dos窗口执行存储过程的时候，我的电脑也不知道是怎么搞的，始终不能粘贴内容，有时候及时粘贴进去内容之后，回车执行的时候，总是出现mysql->   就好像还让你输入下一行了。这里，我推荐大家使用navicat,在navicat中打开命令执行窗口，同样能够看到我们想要的效果，同时我们也不用再手动的设置字符集的编码格式了，方便多了。

下面是运行结果：

 案例二：根据女神名，返回对应的男神名和魅力值

 1 delimiter $
 2 create PROCEDURE     myp8(in beautyName VARCHAR(20),out boyName VARCHAR(20),out userCP INT)
 3 begin
 4         select bo.boyName,bo.userCP into boyName,userCP
 5         from boys bo
 6         INNER JOIN beauty b on bo.id=b.boyfriend_id
 7         where b.name=beautyName;
 8 end $
 9 
10 #调用
11 call myp7(\'小昭\',@bName)$
12 select @bName，@userCP$

运行结果：

 1 mysql> delimiter $
 2 create PROCEDURE     myp8(in beautyName VARCHAR(20),out boyName VARCHAR(20),out userCP INT)
 3 begin
 4         select bo.boyName,bo.userCP into boyName,userCP
 5         from boys bo
 6         INNER JOIN beauty b on bo.id=b.boyfriend_id
 7         where b.name=beautyName;
 8 end $
 9 Query OK, 0 rows affected (0.00 sec)
10 mysql> call myp7(\'小昭\',@bName)$
11 Query OK, 1 row affected (0.00 sec)
12 
13 mysql> select @bName$,@userCP$
14 +--------+
15 | @bName |
16 +--------+
17 | 张无忌 |
18 +--------+
19 1 row in set (0.06 sec)
20 
21 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'@userCP\' at line 1
22 mysql> call myp7(\'小昭\',@bName,@userCP)$
23 1318 - Incorrect number of arguments for PROCEDURE girls.myp7; expected 2, got 3
24 mysql> call myp8(\'小昭\',@bName,@userCP)$
25 Query OK, 1 row affected (0.00 sec)
26 mysql> select @bName$,@userCP$
27 +--------+
28 | @bName |
29 +--------+
30 | 张无忌 |
31 +--------+
32 1 row in set (0.05 sec)
33 
34 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'@userCP\' at line 1
35 mysql> SELECT @userCP$
36 +---------+
37 | @userCP |
38 +---------+
39 |     100 |
40 +---------+
41 1 row in set (0.06 sec)
42 
43 mysql> SELECT @bName,@userCP$
44 +--------+---------+
45 | @bName | @userCP |
46 +--------+---------+
47 | 张无忌 |     100 |
48 +--------+---------+
49 1 row in set (0.06 sec)
50 
51 mysql>