mysql存儲(chǔ)過程中游標(biāo)怎樣遍歷

這篇文章主要介紹了mysql存儲(chǔ)過程中游標(biāo)怎樣遍歷，具有一定借鑒價(jià)值，需要的朋友可以參考下。希望大家閱讀完這篇文章后大有收獲。下面讓小編帶著大家一起了解一下。

mysql存儲(chǔ)過程中游標(biāo)遍歷的方法：首先取值，取多個(gè)字段；然后遍歷數(shù)據(jù)結(jié)束標(biāo)志，將結(jié)束標(biāo)志綁定到游標(biāo)，代碼為【DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;】。

mysql存儲(chǔ)過程中游標(biāo)遍歷的方法：

CREATE DEFINER=`root`@`%` PROCEDURE `updStatus`()
BEGIN
DECLARE startTime DATETIME;
DECLARE endTime DATETIME;
DECLARE curTime DATETIME;
DECLARE id VARCHAR(36); 
DECLARE estatus VARCHAR(4); 
-- 遍歷數(shù)據(jù)結(jié)束標(biāo)志
    DECLARE done INT DEFAULT FALSE;
    -- 游標(biāo)
    DECLARE examIds CURSOR FOR SELECT EXAM_ID FROM t_exam WHERE EXAM_STATUS = 1 or EXAM_STATUS = 2;
    -- 將結(jié)束標(biāo)志綁定到游標(biāo)
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN  examIds;     
    -- 遍歷
    read_loop: LOOP
-- 取值 取多個(gè)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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