对于MySQL，还是菜鸟。
近期做个东西，写了一个MySQL 的存储过程，其中涉及Cursor的使用，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;

关注点有：
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、怎样RUN？输入并执行：call justifyGroupNum()