Question

+----------------+-------------+------+-----+---------+-------+
| Field          | Type        | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+-------+
| attractionID   | varchar(30) | NO   | PRI | NULL    |       |
| attractionName | char(30)    | YES  |     | NULL    |       |
| description    | char(100)   | YES  |     | NULL    |       |
| ticketprice    | int(11)     | NO   |     | NULL    |       |
+----------------+-------------+------+-----+---------+-------+

+--------------+-------------+------+-----+---------+-------+
| Field        | Type        | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| packageNo    | varchar(30) | NO   | PRI | NULL    |       |
| attractionID | varchar(30) | NO   | PRI | NULL    |       |
| numTickets   | int(11)     | NO   |     | NULL    |       |
+--------------+-------------+------+-----+---------+-------+

+---------------+-------------+------+-----+------------+-------+
| Field         | Type        | Null | Key | Default    | Extra |
+---------------+-------------+------+-----+------------+-------+
| packageNo     | varchar(30) | NO   | PRI | NULL       |       |
| passportNo    | varchar(30) | NO   | MUL | NULL       |       |
| fromDate      | date        | NO   |     | 0000-00-00 |       |
| toDate        | date        | NO   |     | 0000-00-00 |       |
| estimatedCost | int(11)     | NO   |     | NULL       |       |
+---------------+-------------+------+-----+------------+-------+


delimiter //
    create trigger estimatedCost_bi
    after insert on ticketBooking
    for each row
    begin
    set @package1=(select(sum(ticketprice*numTickets)
    from attraction join ticketBooking using(attractionID)
    join package using(packageNo) 
    where package.packageNo=new.packageNo);

update package join ticketBooking using(packageNo)

set estimatedCost = @package1

where ticketBooking.packageNo=new.packageNo;
end//
delimiter ;

Answer 1

将来发布问题时，包含错误消息确实很有帮助。在这里。

错误1064（42000）：您的SQL语法有错误;检查与您的MySQL服务器版本相对应的手册，以便在'from attraction join ticketBooking using（attractionID）附近使用正确的语法

这里的基本语法错误就在'from attraction'之前，我们找到了

    set @package1=(select(sum(ticketprice*numTickets)

这里的问题是SELECT（）是无效的语法。正确的语法是SELECT后跟一个空格。这似乎是一个额外的无与伦比的支架，所以您可以像这样删除它：

delimiter //
create trigger estimatedCost_bi
after insert on ticketBooking
for each row
begin
set @package1=(select sum(ticketprice*numTickets)
from attraction join ticketBooking using(attractionID)
join package using(packageNo) 
where package.packageNo=new.packageNo);

使用（packageNo）更新包加入ticketBooking

设置estimatedCost = @ package1

其中ticketBooking.packageNo = new.packageNo; 结束// 分隔符;

我的触发器语法不起作用

1 个答案: