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MySQL的存储过程写法和"Cursor"的使用

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2008-06-01 02:14:22

本文为【MySQL的存储过程写法和"Cursor"的使用】的汉字拼音对照版显示拼音

benwenzhongjieshaoleyigeMySQLdecunchuguochengqizhongshejiCursorde使shiyongshiliruxia

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;

zongjie

1zhuyishezhiyoubiaodecountinue handlerDECLARE CONTINUE HANDLER FOR NOT FOUND set stopFlag=1;

2zhuyiREPEATheUTILE [tingzhitiaojian] END REPEATde使shiyongfouzebuhuixunhuan

3ruheRUNshurubingzhixingcall justifyGroupNum()

原文
 
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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