mysql怎么声明游标

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;