第1个回答 2013-08-30
select (你要查的) from a,b,c
where a.id = b.id and b.id = c.id and (你所要查询出来的条件)
b.id and b.id = c.id 只是把这些表连接起来了
第2个回答 2013-08-30
select * from
A inner join B on A.id=B.id
inner join C on A.id=C.id
第3个回答 2013-08-30
where a.id=b.id and b.id = c.id
第4个回答 2013-08-30
select * from a left join b on a.id=b.id left join c on b.id = c.id;本回答被提问者采纳