mysql存储过程中游标如何遍历

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