create table reserve( flight_number varchar(20) not null unique primary key, take_off_place varchar(20) not null unique, destination varchar(20) not null, flight_time datetime not null, seat_message varchar(20) not null );
create table traveller( t_id int(20) not null unique primary key, name varchar(20) not null, sex varchar(4) not null, tel int(20) not null unique, company varchar(30));
create table ticket( id int(20) not null unique primary key, name varchar(20) not null, flight_number varchar(20) not null unique, entrance varchar(20) not null, take_off_place varchar(20) not null unique, destination varchar(20) not null, flight_time datetime not null, seat_message varchar(20) not null, seat_number int(4) not null unique, constraint t_fk1 foreign key(flight_number,take_off_place,destination,flight_time,seat_message) references reserve(flight_number,take_off_place,destination,flight_time,seat_message), constraint t_fk2 foreign key(name)references traveller(name) )
如果想按照表的意思显示多个信息，除了设置多个主键，还能怎样做啊？
追答我估计到你会问这个
你可以试一下创建约束，就是在插入的时候检查reserve表中是不是有同样值的元组，具体我没有试过。好像mysql没有check语句，所以要用触发器时间，就是在触发器中检查，一旦不一致，就执行一个出错的语句来终止插入或修改
