选择不符合条件的行

Question

I have FEATURE and FEATURE_DETAILS tables. FEATURE_DETAILS can have a lot of FEATUREs.

FEATURE_DETAILS
feature_deatails_id | feature_id
1                        1
1                        2
1                        4 
2                        1
2                        2
2                        4
2                        5

I have a problem in selecting feature_deatails_id's which do not have eg 5 feature_id. So the result should be:

feature_deatails_id | feature_id
1                     null

Answer 1

This should solve your purpose

with data as (
          select 1 as feature_details_id, 1 feature_id from dual
    union select 1,2 from dual
    union select 1,4 from dual
    union select 2,1 from dual
    union select 2,2 from dual
    union select 2,4 from dual
    union select 2,5 from dual
)
select distinct feature_details_id, NULL feature_id from data
where feature_details_id not in (
      select feature_details_id from data
      where  feature_id = 5)
;

What the above query will do is -

1. Select the feature_details_id where feature = 5
2. Remove all those feature_details_id and select whatever is remaining

Answer 2

With a NOT IN should be ok

SELECT DISTINCT FEATURE_DETAILS_ID, NULL AS FEATURE_ID 
    FROM FEATURE_DETAILS 
    WHERE FEATURE_DETAILS_ID NOT IN (
        SELECT FEATURE_DETAILS_ID FROM FEATURE_DETAILS WHERE FEATURE_ID = 5
    );

Answer 3

select feature_deatails_id, null as feature_id from feature_details where feature_id != 5

This should solve your purpose.