Hi,

Yes, it's already reported:

http://sourceforge.net/tracker/index.php?
func=detail&aid=919713&group_id=9028&atid=109028

You can work around it by using a subselect:

select xxx from mytable where not exists (select x from table2 where
table2.id = mytable.id)

--- In firebird-support@yahoogroups.com, "chiaraprc"
<chiaraprc@y...> wrote:

> Hi I think this is a bug....
>
> CREATE TABLE TableA (
> Field1 VARCHAR(10)
> );
>
> CREATE TABLE TableB (
> Field2 VARCHAR(10)
> );
>
> INSERT INTO TableA (Field1 ) VALUES ('A');
> INSERT INTO TableA (Field1 ) VALUES ('B');
> INSERT INTO TableA (Field1 ) VALUES ('C');
>
> INSERT INTO TableB (Field2 ) VALUES ('B');
> INSERT INTO TableB (Field2 ) VALUES ('C');
> INSERT INTO TableB (Field2 ) VALUES ('D');
>
>
> This work as expected
> ****************************************
> Select TA.Field1, TB.Field2
> From TableA TA
> Full Join TableB TB On TA.Field1=TB.Field2
> order by 1,2
>
> Field1 Field2
> ========== ==========
>
> A <null>
> B B
> C C
> <null> D
>
>
> This *DONT* work as expected
> ****************************************
> Select TA.Field1, TB.Field2
> From TableA TA
> Full Join TableB TB On TA.Field1=TB.Field2
> Where TB.Field2 Is Null
>
>
>
> Field1 Field2
> ========== ==========
>
> A <null>
> B <null>
> C <null>
>
>
>
> Server Version WI-V1.5.0.4306 Firebird 1.5