Thanks to all the EXEPT keyword is what I was looking for
On Thu, May 22, 2008 at 5:36 PM, Niklas Johansson <spot@tele2.se> wrote:
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.
