| Subject | RE: [firebird-support] Unique index NULL == NULL? |
|---|---|
| Author | Dmitry Yemanov |
| Post date | 2003-11-13T07:46:33Z |
Helen,
non-null segments are distinct. So (1, NULL, NULL) = (1, NULL, NULL), but
(NULL, NULL, NULL) <> (NULL, NULL, NULL).
Dmitry
> >This seems to indicate to me that (1, NULL, NULL) <> (1, NULL,Nope, that's incorrect. Two unique index keys are considered distinct if all
> >NULL), because all segments are not non-null. Is that correct?
>
> It is supposed to be. However, a bug seems to have shown up.
non-null segments are distinct. So (1, NULL, NULL) = (1, NULL, NULL), but
(NULL, NULL, NULL) <> (NULL, NULL, NULL).
Dmitry