求个SQL！
存在A、B、C表
A表
id 
0
1
2

B表
aid name
0 b
2 b

C表
aid name
1 c

得到A表关联B表数据或关联C表数据（判断A id是否存在B表，存在则关联，反关联C表）
得到
id name
0 b
1 c
2 b

------解决方案--------------------
select * from A inner join (select * from B left join C on B.id=C.id) as D on A.id=D.id
------解决方案--------------------
select A.id,(case when isnull(B.name,'')='' then C.name else B.name end) name from A 
left outer join B on A.id=B.aid 
left outer join (select * from C where aid not in(select aid from b)) c on A.id=c.aid
order by A.id

给分哦
------解决方案--------------------
select A.ID, name= case when b.id is not null then b.name else c.name end from A left join B on A.ID =B.ID 
left join C on A.ID = C.ID

------解决方案--------------------
select * from B where id exists (select id from A)
union 
select * from C where aid exists (select id from A)

这样嘛？
------解决方案--------------------

SQL code

select A.ID,CASE WHEN B.name IS NULL THEN C.Name else B.Name end Name from A left join B on A.ID=B.AID
left join C on A.ID=C.AID

------解决方案--------------------
id	name
0	B
1	C
2	B

你确定不好使，这是我照你的表创建的，执行SQL后很你显示的结果也一致，你到底需要什么效果，请表达清楚