Incorrect number of FETCH variables

在写存储过程，运行后提示“Incorrect number of FETCH variables”

原来是用游标select的字段数需要与fetch into的变量数一致

修改后的如下：

DROP PROCEDURE IF EXISTS modify_recommend_merchant;DELIMITER //CREATE PROCEDURE modify_recommend_merchant()BEGINDECLARE dat DATETIME DEFAULT DATE_SUB(NOW(), INTERVAL 1 DAY);DECLARE m_id INT;DECLARE done INT DEFAULT 0;DECLARE cur CURSOR FOR SELECT merchant_id FROM merchant WHERE is_recommend = 1 AND biz_type = 1 AND STATUS = 1;DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;OPEN cur;l1:LOOPFETCH cur INTO m_id;IF done = 1 THEN LEAVE l1;END IF;SET dat = DATE_ADD(dat, INTERVAL 1 SECOND);UPDATE merchant SET recommend_time = dat WHERE merchant_id = m_id;END LOOP l1;CLOSE cur;END//DELIMITER ;CALL modify_recommend_merchant;