Re: multiple identical constraints

From: Van Messner <vmessner_at_netaxis.com>
Date: Mon, 3 May 1999 18:45:42 -0400
Message-ID: <gMpX2.3043$fO5.102490@news14.ispnews.com>

You can get multiple constraints if you define a column as not null, then make that column part of a primary key. In that case dropping the not null constraint while leaving the primary key constraint intact will cause no harm.

Van

dyrdahl_at_my-dejanews.com wrote in message <7gch5t$s9u$1_at_nnrp1.dejanews.com>...
>I am working on a database which someone else created. This is an Oracle 8
>database running on a NT server. I believe that the tables, indexes, etc.
>were originally created using the graphical interface provided by Oracle.
I
>was looking at the all_con_columns view and noticed that there are numerous
>columns which have duplicate constraints.
>
>In other words, they created a column with a not null constraint. However,
>there are actually two not null constraints for the same column. I am
>assuming that this is a bad idea since every update/insert will check the
>same condition twice.
>
>Before I go and drop a bunch of these constraints, I wanted to know if
anyone
>could see why there would be two and also if it matters which one of the
two
>that I drop? Thanks.
>
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Received on Mon May 03 1999 - 17:45:42 CDT