I wonder why I don't get an exception on delphi?

I'm using Delphi (windows) to develop a  database application using Postgres
7.1 in linux.
When I use delphi with other databases and I try to insert a record that
violates referential integrity I get an exception, but with postgres I
don't, I tried to insert the same record on PSQL and I get an error, could
it be the ODBC driver?

Please help me, if you know...


Thank you.

Ligia