MySQL 存储过程游标的简单用法

代码：

delimiter $create PROCEDURE PROC_COUPON_TIMING_TASK()BEGIN        -- 定义变量        DECLARE key_Id INT DEFAULT 0;        -- 遍历数据结束标志    DECLARE done INT DEFAULT FALSE;    -- 游标    DECLARE coupon_data CURSOR FOR SELECT u.id FROM xsxx_store_user_coupon u         LEFT JOIN xsxx_store_coupon c on u.coupon_id = c.id        WHERE NOW() >= c.end_time and u.status = 0;    -- 将结束标志绑定到游标    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;    -- 打开游标    OPEN  coupon_data;         -- 遍历    read_loop: LOOP            -- 取值            FETCH  NEXT from coupon_data INTO key_Id;            IF done THEN                LEAVE read_loop;             END IF;        -- 将到期的优惠券修改状态为-1                UPDATE xsxx_store_user_coupon SET `status` = -1 WHERE id = key_Id;        END LOOP;        -- 关闭游标        CLOSE coupon_data;END