MySQL--带有inout的存储过程

#带有inout模式参数的存储过程

 1 案例一：传入a和b两个值，最终a和b的值翻倍并返回
 2 delimiter $
 3 create PROCEDURE myp9(inout a int,inout b int)
 4 begin
 5      set a=a*2;
 6          set b=b*2;
 7 end $
 8 
 9 调用过程
10 先设置两个用户变量
11 set @m=10$
12 set @n=20$
13 然后调用
14 call myp9(@m,@n)$
15 select @m,@n$--最后查看结果

运行结果:

 1 mysql> delimiter $
 2 create PROCEDURE myp9(intout a int,inout b int)
 3 begin
 4      set a=a*2;
 5          set b=b*2;
 6 end $
 7 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 'a int,inout b int)
 8 begin
 9      set a=a*2;
10          set b=b*2;
11 end' at line 1
12 mysql> delimiter $
13 create PROCEDURE myp9(inout a int,inout b int)
14 begin
15      set a=a*2;
16          set b=b*2;
17 end $
18 Query OK, 0 rows affected (0.00 sec)
19 
20 mysql> set @a=10$
21 Query OK, 0 rows affected (0.00 sec)
22 
23 mysql> set @b=20$
24 Query OK, 0 rows affected (0.00 sec)
25 
26 mysql> call myp9(@a,@b)$
27 Query OK, 0 rows affected (0.00 sec)
28 
29 mysql> select @a,@b$
30 +----+----+
31 | @a | @b |
32 +----+----+
33 | 20 | 40 |
34 +----+----+
35 1 row in set (0.06 sec)
36 
37 mysql>