Message-ID: <44E6C30D.1070608@logix-tt.com>
Date: Sat, 19 Aug 2006 09:51:41 +0200
From: Markus Schaber <schabi@logix-tt.com>
Organization: Logical Tracking and Tracing International AG, Switzerland
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To: Julian Scarfe <julian@avbrief.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: NULL becomes default
References: <029c01c6c228$8e8e5210$0600a8c0@Wilbur>
In-Reply-To: <029c01c6c228$8e8e5210$0600a8c0@Wilbur>
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Hi, Julian,

Julian Scarfe wrote:
> A surrogate key has been introduced on a table with modifiers:
> 
>   Column    |            Type             | Modifiers
> -------------+-----------------------------+------------------------------------------------------------
> 
> new_id    | integer                     | not null default
> nextval(('some_id_seq'::text)::regclass)
> 
> However, some legacy software inserts into the table by first getting
> column names and then composing an INSERT for all the columns, filling
> in any undefined values with NULLs.
> 
> Thus when it attempts to insert a row I get a:
> 
> ERROR:  null value in column "new_id" violates not-null constraint
> 
> Thus I would like NULLs in such INSERTs to be treated as DEFAULT rather
> than violating the constraint.  Is there an easy way to do that at the
> database level?

Did you try a "before insert" trigger that checks new_id for null
values, and replaces it with nextval()?

Markus


-- 
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

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