mysql声明游标的方法

declare result varchar(3000);
declare flag1 varchar(100);
DECLARE done INT DEFAULT FALSE;
declare cur1 CURSOR FOR SELECT flag from bmlx;

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
set result = '';

open cur1;
read_loop: LOOP

FETCH cur1 INTO flag1;

IF done THEN
LEAVE read_loop;
END IF;

set result = CONCAT(result, flag1 ,',');
END LOOP;

close cur1;

set result = CONCAT(result,'<span style="color:Red">');
RETURN result;

DECLARE calc_bonus CURSOR FOR SELECT id, salary, commission FROM employees;

OPEN calc_bonus;

FETCH calc_bonus INTO re_id, re_salary, re_comm;

CLOSE calc_bonus;