在SQL中使用不同条件两次获取同一列

Question

I would like to retrive same columns twice but with different conditions.

my Query is like this but the following Query retrives two different columns. But I want to get the same column twice, How can I achieve this?

Select name from tbCustomer where ID in (select ID from tbOldCustomer where oldID= 1)
Select name from tbCustomer where ID in (select ID from tbOldCustomer where oldID= 2)

tbCustomer has two columns:
ID name
1 aaa
2 bbb
3 ccc
4 ddd

tbOldCustomer has two columns:

ID oldID
1 2
2 1
3 1
4 2
4 1

would like to get name where oldID in (1, 2) and the output should be the follwing:

name name1
bbb aaa
ccc ddd
ddd

Answer 1

use exists

select t1.name 
from tbCustomer t1 
exists( select 1 from  tbOldCustomer t2  where  t1.id = t2.id
                                       and t2.oldid in (1,2)
        )

Answer 2

I think you can achieve that by using simply JOIN

Select name 
from tbCustomer tc 
inner join tbOldCustomer toc On toc.id = tc.id
where toc.oldID IN (1,2)

Answer 3

you can try using conditional aggregation with case when expression

select max(case when oldID= 1 then name end) as name1,
       max(case when oldID= 2 then name end) as name2
from tbCustomer join tbOldCustomer on ID=oldID where oldid in (1,2)
group by oldid

Answer 4

You have to try

Select tc.name, toc.name from tbCustomer tc inner join 
tbOldCustomer toc On toc.id = c.id where toc.oldID IN (1,2)

Answer 5

Please try this.

Select name from tbCustomer where ID in (select ID from tbOldCustomer where oldID IN(1,2))

OR

Select A.name from tbCustomer A
INNER JOIN tbOldCustomer  B
ON A.id = B.Id
AND B.OldId In (1,2)

Answer 6

Try this

SELECT  name 
FROM tbCustomer tb1 
JOIN (SELECT ID FROM tbOldCustomer WHERE oldID = 1 OR oldID= 2) tb2
     ON tb1.ID = tb2.ID
WHERE tb1.ID IN (SELCT ID from tbOldCustomer where oldID in (1, 2))