Question

当我尝试执行此过程时，它显示错误。

USE `metro`;
DROP procedure IF EXISTS `transaction`;

DELIMITER $$
USE `metro`$$
CREATE DEFINER=`root`@`localhost` PROCEDURE `transaction`(
IN amount_p INT,
IN id_in INT,
IN id_out INT,
IN uidd INT
)
BEGIN

DECLARE uide INT;
DECLARE amt INT;
DECLARE NOW_AMT INT DEFAULT 0;

SELECT `amount` INTO amt FROM metro.wallet WHERE `uid`=uide;
INSERT INTO metro.transactions(`amount_deducted`,`time`,`station_id_in`,`station_id_out`,`uid`)
VALUES (amount_p,now(),id_in,id_out,uid);
SELECT uidd INTO uide;
SELECT uide;
SET NOW_AMT:=@amt+amount_p;

SELECT amt;
UPDATE metro.wallet SET `uid`=uide,`amount`=NOW_AMT;

END$$

DELIMITER ;

wallet是一个包含uid和amount列的表。

错误代码1048，SQL状态23000：列＆＃39;数量＆＃39;不能为空第1行第1列

执行0秒后完成，发生1个错误。

执行：

call metro.transaction(112,1,1,1);

Answer 1

或许将您的AMOUNT包装在一个case语句中，如果它是NULL，您可以返回默认值。

SELECT case when `amount` is NULL then '' else `amount` END as `amount` INTO amt FROM metro.wallet WHERE `uid`=uide;

Mysql错误嵌套算术在select中

1 个答案: