SQL 查询返回与具有特定值的另一列关联的列

Question

COL1	COL2
10068	CP
10068	DF
10068	DP
10069	CP
10061	CP

I have this table and I am trying to write a SQL query in Oracle, such that it fetches col1s that have corresponding col2 as 'CP' only and nothing else. In above example, data returned should be 10069 and 10061, it should not return 10068 as it has DF and DP as well associated.

Below is my query but it doesn't work, it is fetching col1 with 10068 as well

SELECT DISTINCT COL1, COL2 
FROM SAMPLETABLE 
WHERE COL2 NOT IN ('DF', 'DP')

Can someone help please?

Answer 1

You can use group by and having :

select col1
from sampletable t
group by col1
having min(col2) = max(col2) and min(col2) = 'CP'

Answer 2

You can use not exists

 create table SAMPLETABLE ( COL1 int, COL2 varchar(10));


 insert into SAMPLETABLE values(10068,  'CP');
 insert into SAMPLETABLE values(10068,  'DF');
 insert into SAMPLETABLE values(10068,  'DP');
 insert into SAMPLETABLE values(10069,  'CP');
 insert into SAMPLETABLE values(10061,  'CP');

Query:

 select col1,col2 from sampletable a
 where not exists
                 (select 1 from sampletable b where a.col1=b.col1 and b.col2<'CP')

Output:

COL1	COL2
10061	CP
10069	CP

Or you can also use group by with having clause:

Query:

select col1  from SAMPLETABLE 
 group by col1
 having count(distinct col2)=1
 and min(col2) ='CP'

Output:

COL1
10061
10069

db<>fiddle here