表A
字段 a,b,c,d,e,f
表B l,m,n
A.e 和 B.l 关联 根据 A.e 查询 B.m
A.f 和 B.l 也关联 根据 A.f 查询 B.m
最后要查询
A.a,A.e(替换为B.m),A.f(替换为B.m)
两表关联查询
谢谢
------解决方案--------------------
select *
from a join b on a.e = b.l and a.f = b.m
------解决方案--------------------
select X.a,Y.m,Z.m
from A x inner join B y on y.l = X.e
inner join B z on z.l = X.f
------解决方案--------------------
自己从 * 里选择要查询的列。
------解决方案--------------------
- SQL code
select a.a,b.m,c.mfrom ajoin b on a.e=b.ljoin b as c on a.f=c.l
------解决方案--------------------
selex X.a,Y.m,Z.m
from A X inner join B Y on Y.l = X.e
inner join Z on Z.l = X.f
------解决方案--------------------
selex X.a,Y.m,Z.m
from A X inner join B Y on Y.l = X.e
inner join B Z on Z.l = X.f