create table users ( uid int not null primary key, uname varchar(10) ) go create table trade ( tid int not null primary key, buyuserid int not null, selluserid int not null ) go alter table trade add constraint FK_buyuserid foreign key(buyuserid) references users(uid); alter table trade add constraint FK_selluserid foreign key(selluserid) references users(uid); go insert into users values(1, 'aaa '); insert into users values(2, 'bbb '); insert into users values(3, 'ccc '); insert into users values(4, 'ddd '); insert into users values(5, 'eee '); go insert into trade values(1,1,3); insert into trade values(2,2,4); insert into trade values(3,2,3); insert into trade values(4,3,5); go select * from users; select * from trade; --买 select count(trade.buyuserid) as buycount,trade.buyuserid,min(users.uname) as buyusername from trade,users where trade.buyuserid=users.uid group by trade.buyuserid; --卖 select count(trade.selluserid) as sellcount,trade.selluserid,min(users.uname) as sellusername from trade,users where trade.selluserid=users.uid group by trade.selluserid;
应该可以吧 试试