如果没有主键则按下面写: select * from A where not exists(select 1 from B where username=A.username and point=A.point) 如果有主键则按下面写: select * from A where not exists(select 1 from B where 主键=a.主键)
select A.* from A,B where A.username <>B.username and A.point<>B.point
select * from A where not exists(select * from B where username=A.username and point=A.point)
select * from A where not exists(select 1 from B where username=A.username and point=A.point)
如果有主键则按下面写:
select * from A where not exists(select 1 from B where 主键=a.主键)
where A.username <>B.username
and A.point<>B.point
好像这样写没对吧1!
我是感觉有点怪。