:: >Select * From TEST_TBT
:: > Where (i=1) AND (Field_1 = 'AAA') OR (i=2) AND Field_2 = 'BBB';
::
:: Cute! :-)

You can do some neat tricks on this variant with unions too. Before we used
a framework to do transofrmations and were doing simple client server apps
we had to do all kinds of wierdo SQL tricks.