这篇文章主要介绍了mysql存储过程中游标怎样遍历,具有一定借鉴价值,需要的朋友可以参考下。希望大家阅读完这篇文章后大有收获。下面让小编带着大家一起了解一下。
mysql存储过程中游标遍历的方法:首先取值,取多个字段;然后遍历数据结束标志,将结束标志绑定到游标,代码为【DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;】。
CREATE DEFINER=`root`@`%` PROCEDURE `updStatus`()
BEGIN
DECLARE startTime DATETIME;
DECLARE endTime DATETIME;
DECLARE curTime DATETIME;
DECLARE id VARCHAR(36);
DECLARE estatus VARCHAR(4);
-- 遍历数据结束标志
DECLARE done INT DEFAULT FALSE;
-- 游标
DECLARE examIds CURSOR FOR SELECT EXAM_ID FROM t_exam WHERE EXAM_STATUS = 1 or EXAM_STATUS = 2;
-- 将结束标志绑定到游标
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN examIds;
-- 遍历
read_loop: LOOP
-- 取值 取多个字段
FETCH NEXT from examIds INTO id;
IF done THEN
LEAVE read_loop;
END IF;
SELECT EXAM_STATUS INTO estatus FROM t_exam WHERE EXAM_ID = id ;
IF estatus =1 THEN
SELECT NOW() INTO curTime;
SELECT EXAM_START_TIME INTO startTime from t_exam WHERE EXAM_ID = id ;
SELECT EXAM_END_TIME INTO endTime from t_exam WHERE EXAM_ID = id ;
IF curTime >= startTime AND endTime > curTime THEN
UPDATE t_exam SET EXAM_STATUS = 2 WHERE EXAM_ID = id;
ELSEIF curTime >= endTime THEN
UPDATE t_exam SET EXAM_STATUS = 3 WHERE EXAM_ID = id;
END IF;
ELSE
SELECT NOW() INTO curTime;
SELECT EXAM_END_TIME INTO endTime from t_exam WHERE EXAM_ID = id ;
IF curTime >= endTime THEN
UPDATE t_exam SET EXAM_STATUS = 3 WHERE EXAM_ID = id;
END IF;
END IF;
END LOOP;
CLOSE examIds;
END
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