MySQL的存储过程写法和“Cursor”的使用

2008-03-11

eNet&Ciweek

本文中介绍了一个MySQL的存储过程，其中涉及Cursor的使用，示例如下：

CREATE PROCEDURE `justifyGroupNum`()

NOT DETERMINISTIC

SQL SECURITY DEFINER

COMMENT ''

BEGIN

/*how to run:call justifyGroupNum()*/

DECLARE p_group_id int;

declare p_num int;

declare stopFlag int;

DECLARE cursor_name CURSOR

FOR select c_group_id,count(*) as num

from `t_group_member`

where c_valid in (3,4)

group by c_group_id;

DECLARE CONTINUE HANDLER FOR NOT FOUND set stopFlag=1;

OPEN cursor_name;

REPEAT

FETCH cursor_name INTO p_group_id,p_num;

begin

update t_groupinfo set c_member_number=p_num where c_group_id=p_group_id;

end;

UNTIL stopFlag = 1

END REPEAT;

CLOSE cursor_name;

END;

总结：

1、注意设置游标的countinue handler：DECLARE CONTINUE HANDLER FOR NOT FOUND set stopFlag=1;

2、注意REPEAT和UTILE [停止条件] END REPEAT的使用，否则不会循环；

3、如何RUN，输入并执行：call justifyGroupNum()

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