mysql声明游标的方法：

1、声明变量和游标

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

2、变量赋值

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

3、打开游标和循环

open cur1;
read_loop: LOOP

-- 给游标赋值

FETCH cur1 INTO flag1;

-- 跳出循环

IF done THEN
LEAVE read_loop;
END IF;

-- 循环获取游标数据，进行累加

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

-- 关闭游标

close cur1;

-- 返回参数

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

内容扩展：

mysql游标使用的整个过程为：

1.创建游标

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

2.打开游标

OPEN calc_bonus;

3.使用游标

FETCH calc_bonus INTO re_id, re_salary, re_comm;

4.关闭游标

CLOSE calc_bonus;