From: | "Marin Dimitrov" <marin(dot)dimitrov(at)sirma(dot)bg> |
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To: | <hoanui(at)excite(dot)com>, <pgsql-jdbc(at)postgresql(dot)org> |
Subject: | Re: select * from mytable where myfield=null; |
Date: | 2002-05-14 13:54:21 |
Message-ID: | 00b701c1fb4e$d9532410$9ba1d53e@sirma.bg |
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Lists: | pgsql-jdbc |
----- Original Message -----
From: "Hoanui Morangie"
>
> I need NULL value, some of these columns are foreign keys.
introduce dummy tupples too, f.e. if u consider 0 as the NULL for numbers,
then have a dummy row with ID=0, so that the FK won't be violated and u'll
still have NULL semantics
>And using dummy values is not good practice anyway.
>
indeed, 3-valued logic (nulls) is often considered as a flaw and NULL usage
is not recommended.
And in your case u won't make use of any indexes for the queries, because
these null values can't be indexed
Marin
----
"...what you brought from your past, is of no use in your present. When
you must choose a new path, do not bring old experiences with you.
Those who strike out afresh, but who attempt to retain a little of the
old life, end up torn apart by their own memories. "
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