ODP: [firebird-support] Unique Constraints and NULLs

[Karol Bieniaszewski liviusliv...@poczta.onet.pl [firebird-support]]

Hi,

If you do not need referential constraint based on this unique only you need to 
have uniques.
Then you can simply create expression index, e.g.:

CREATE UNIQUE INDEX IXAE_blah_C1C2 ON blach COMPYTED BY(COL1 || ‘_‘ || 
COALESCE(COL2));

Regards,
Karol Bieniaszewski