From: Chris Travers <chris@travelamericas.com>
To: Matt L. <survivedsushi@yahoo.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: nullif('','') on insert
Date: Fri, 26 Aug 2005 23:45:25 -0700
Message-ID: <43100C05.7020309@travelamericas.com> (raw)
In-Reply-To: <20050821014023.92296.qmail@web35209.mail.mud.yahoo.com>
References: <20050821014023.92296.qmail@web35209.mail.mud.yahoo.com>
Matt L. wrote:
>I need to test whether or not a value is null on
>insert.
>
>Example: insert into table (column) values
>nullif('',''));
>ERROR: column "column" is of type boolean but
>expression is of type text.
>
>
Your problem is that NULL's are typed in PostgreSQL.
Try this:
SELECT NULL;
SELECT NULL::BOOL;
SELECT NULL::BOOL::TEXT;
to see what I mean. This is an exact illustration of your problem.
>It works in MSSQL (probably against not standards) but
>nonetheless I need to make it work.
>
>I assume it's returning 'NULL' w/ quotes?
>
Nope. It is returning a text string which is valued at NULL. It cannot
convert a text string to a BOOL (even if the string is a NULL) so it
gives you an error.
> I don't know
>where to look to alter it. I looked into functions but
>all I see is how to write "AS queries" or point to
>various snippets. I'd rather just alter the nullif
>function.
>
>
SELECT NULLIF('' = '', TRUE);
Does this work? You could write a wrapper function if necessary.....
Best Wishes,
Chris Travers
Metatron Technology Consulting
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To: pgsql-sql@postgresql.org
Cc: chris@travelamericas.com, survivedsushi@yahoo.com
Subject: Re: nullif('','') on insert
In-Reply-To: <43100C05.7020309@travelamericas.com>
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