MySQL Trigger：查询内部查询错误的变量引用

Question

我创建了一个触发器：

DELIMITER $$
CREATE TRIGGER member_enrollment_update AFTER UPDATE ON memberships
FOR EACH ROW
BEGIN

INSERT INTO query_logs (QUERY,shop_id) VALUES ("update memberships set member_enrollment_status="+NEW.member_enrollment_status+" where card_no ='"+NEW.card_no+"'","LR00");

END $$
DELIMITER ;

其中列的数据类型为：

member_enrollment_status int(1) DEFAULT 0 ,
card_no varchar(15) NOT NULL

执行更新时，执行的SQL为：

update memberships set member_enrollment_status= 1 where card_no=3678000022 and member_enrollment_status = 0

警告是：

1292 - Truncated incorrect DOUBLE value: '''
1292 - Truncated incorrect DOUBLE value: ' where card_no =''
1292 - Truncated incorrect DOUBLE value: 'update memberships set member_enrollment_status='
In query_logs table, record is inserted but getting only the card_no (3678000022) as value of QUERY column.

请帮助解决错误

Answer 1

我没有使用+作为连接，而是使用INSERT INTO语句中的CONCAT函数来解决问题。

INSERT INTO query_logs (QUERY,shop_id) 
VALUES 
(CONCAT("update memberships set member_enrollment_status=", NEW.member_enrollment_status,  
        "where card_no ='", NEW.card_no, "'"), "LR00");