如何在mysql中声明触发器中的值？

我正在尝试使用mysql和phpmyadmin为我的数据库编写触发器。我有一个数据库，其中有一个用于存储客户信息的表，其中存储了信用卡号码，还有一个用于存储酒店预订的表，其中存储了客户的付款方式。我想我的触发器激活后更新客户的信息，如果信用卡号被删除，以改变付款方式。问题是phpmyadmin没有编译它

CREATE TRIGGER after_credit_card_update
AFTER UPDATE  
ON client
for each row
BEGIN
       declare cl_id int;
       IF ( (new.Credit_Card_Number = " ") or (new.Credit_Card_Number is null)) then
select into cl_id
                select reservation.Client_Id from 
reservation where ((reservation.Client_Id = new.Client_Id) and (reservation.Payment = 'Credit')) 
limit 1 ;
    update reservation
    set reservation.Payment = "NOT PAID"
    where reservation.Client_Id = cl_id;
END IF;
END$$

我相信问题是当我声明我的价值时：cl_id

1064-您的SQL语法有错误；查看与您的MySQL服务器版本对应的手册，以了解第8行中“into cl_id select reservation.Client_id from reservation where”附近使用的正确语法 固定的：

DELIMITER $$
CREATE TRIGGER after_credit_card_update
AFTER UPDATE  
ON client
for each row
BEGIN
declare cl_id int;
IF ( (new.Credit_Card_Number = " ") or 
new.Credit_Card_Number is null)) then
 select reservation.Client_Id into cl_id from reservation 
here ((reservation.Client_Id = new.Client_Id) and 
reservation.Payment = 'credit')) 
limit 1 ;
update reservation
set reservation.Payment = "NOT PAID"
where reservation.Client_Id = cl_id;
END IF;
END$$

---

定界符

这里不详细介绍，但您需要在触发器前后添加

分隔符

语句，以便MySQL知道如何解析代码。例如：

---

在尝试创建过程之前，您是否将分隔符设置为

$

？是的，我仍然没有执行任何操作我复制粘贴了您的解决方案，但它仍然不起作用

DELIMITER $$

CREATE TRIGGER after_credit_card_update
AFTER UPDATE  
ON client
for each row
BEGIN
       declare cl_id int;
       IF ( (new.Credit_Card_Number = " ") or 
new.Credit_Card_Number is null)) then
select into cl_id
                select reservation.Client_Id from 
reservation where reservation.Client_Id = new.Client_Id 
limit 1 ;
    update reservation
    set reservation.Payment = "NOT PAID"
    where reservation.Client_Id = cl_id;
END IF;
END$$

DELIMITER ;