Hi,

I'm still using fb 1.5.3 SS version and got an strange error. I want
to create a foreign key constraint in table CURS_SEGUIMENT as follows:

alter table CURS_SEGUIMENT
add constraint FK_CURS_SEGUIMENT_CURS
foreign key (IDCURS)
references CURS (ID)
on update NO ACTION
on delete NO ACTION


but when commiting transaction it raises next error (with flamerobin):

Starting transaction...
Preparing query: alter table CURS_SEGUIMENT
add constraint FK_CURS_SEGUIMENT_CURS
foreign key (IDCURS)
references CURS (ID)
on update NO ACTION
on delete NO ACTION
Prepare time: 00:00:02.
Plan not available.


Executing...
Done.
390 fetches, 14 marks, 0 reads, 0 writes.
4 inserts, 1 updates, 0 deletes, 102 index, 0 seq.
Delta memory: 3472 bytes.
RDB$INDEX_SEGMENTS: 1 inserts.
RDB$INDICES: 1 inserts. Commiting transaction...

RDB$RELATIONS: 1 updates.
RDB$RELATION_CONSTRAINTS: 1 inserts.
RDB$REF_CONSTRAINTS: 1 inserts.
Execute time: 00:00:09.
*** IBPP::SQLException ***
Context: Transaction::Commit

SQL Message : -607
This operation is not defined for system tables.

Engine Code : 335544351
Engine Message :
unsuccessful metadata update
object CURS is in use


I tried with another database manager and no luck. I have restarted fb
service and error raise again. The last thing I tried was deleting all
rows from CURS_SEGUIMENT before creating constraint and no luck again.
What's wrong?!?!


Best regards
Julian.