急啊!帮忙回答一下!谢谢!

应该是。。。。。。。哈哈

select *
多表查询
from tablea as a inner join tableb as b
on a.id=b.id
where .....

还可以用
SELECT * FROM tablea
UNION
SELECT * FROM tableb

把不同表的相同字段组合到一张表里

select *
from a left/*或者right*/ join b
on a.id=b.id
where .....
还可以用
SELECT * FROM a
UNION
SELECT * FROM b