帶有多列的SQL查詢加入

Question

我面臨着一個問題：

table1的

C1 C2 C3 tempId 
1 4  5 ab 
2 6  7 fc 
3 8  9 vb 

表2

ids val 
1  a 
2  b 
3  c 
4  d 
5  e 
6  f 
7  g 
8  h 
9  i 

我想通過tempId即AB的價值，並希望像輸出

valofc1 valofc2 valofc3 
a   d  e 

請幫助我不要不知道如何實現這一點。

Answer 1

試試這個

select t2.val valofc1,t3.val valofc2,t4.val valofc3 from table1 t1 
    inner join table2 t2 on t1.C1 = t2.ids 
    inner join table2 t3 on t1.C2 = t3.ids 
    inner join table2 t4 on t1.C3 = t4.ids 
    where tempId = 'ab' 

DEMO HERE

Answer 2

試試這個方法：

select t21.val as valofc1, t22.val as valofc2, t23.val as valofc3 
from table1 as t 
join table2 as t21 on t21.ids = t.C1 
join table2 as t22 on t22.ids = t.C2 
join table2 as t23 on t23.ids = t.C3 
where t.tempId = 'ab' 

Answer 3

Declare @t table (C1 int,C2 int,C3 int,tempId varchar(50)) 
insert into @t values (1,4,5,'ab'),(2,6,7,'fc'),(3,8,9,'vb') 
Declare @table2 table (id int,val varchar(50)) 
insert into @table2 values(1,'a'),(2,'b'),(3,'c'),(4,'d'),(5,'e'),(6,'f'),(7,'g'),(8,'h'),(9,'i') 
select 
(select val from @table2 where id=t.C1)valofc1 , 
(select val from @table2 where id=t.C2)valofc2, 
(select val from @table2 where id=t.C3)valofc3 
from @t t where tempid='ab' 

在RDBMS