On 22 maj 2008, at 17.15, Nacef LABIDI wrote:
> I was wondering how can I substract result between select queries.
> I mean I want to issue a query that does this :
> (select * from mytable where condition1) - (select * from mytable
> where condition2)
If you (as implied above) query the same table in both cases, just do:
SELECT * FROM mytable WHERE condition1 AND NOT condition2
Otherwise, use EXCEPT:
SELECT * FROM mytable1 WHERE condition1
EXCEPT
SELECT * FROM mytable2 WHERE condition2
in which case both queries must return the same type of rows.
Sincerely,
Niklas Johansson
