Question

I have a table in which i have multiple entries against a FK. I want to find out the value of FK which do not have certain entries e.g
my table has following entries.

PK----------------FK-----------------Column entries

1----------------100-----------------ab1
2----------------100-----------------ab2
3----------------100-----------------ab4
4----------------200-----------------ab1
5----------------200-----------------ab2
6----------------200-----------------ab3
7----------------300-----------------ab1
8----------------300-----------------ab2
9----------------300-----------------ab3
10---------------300-----------------ab4

Now, from this table i want to filter all those FK which do not have ab3 or ab4 in them. Certainly, i expect distinct values i.e. in this case result would be FK= 100 and 200.
The query which i am using is

select distinct(FK) 
from table1 
where column_entries != 'ab3' 
   or column_entries != 'ab4';

Certainly, this query is not fetching the desired result.

Answer 1

try the following :-

select distinct fk_col from table1
minus
(select distinct fk_col from table1 where col_entry='ab3'
intersect
select distinct fk_col from table1 where col_entry='ab4')

This will show all those FKs which do not have ‘ab3’ and ‘ab4’. i.e. 100 and 200 in your case