From: Tomasz Myrta <jasiek@klaster.net>
To: Kumar <sgnerd@yahoo.com.sg>
Cc: psql <pgsql-sql@postgresql.org>
Subject: Re: How to avoid nulls while writing string for dynamic query
Date: Fri, 13 Feb 2004 09:07:15 +0100
Message-ID: <402C85B3.2020204@klaster.net> (raw)
In-Reply-To: <00c801c3f200$e117eff0$7502a8c0@hdsc.com>
References: <00c001c3f164$1db30140$7502a8c0@hdsc.com>
<402B74F4.7070604@klaster.net>
<006701c3f1ed$6610dc30$7502a8c0@hdsc.com>
<402C6FB8.8000606@klaster.net>
<00c801c3f200$e117eff0$7502a8c0@hdsc.com>
Dnia 2004-02-13 08:13, Użytkownik Kumar napisał:
> oh, ok understood.
> What will happen for a timestamp field. Let us say c1 is a timestamp column.
>
> sqlstr := 'insert into test(c1, c2) values
> ('||'\''||COALESCE(rec.c1,'NULL')||'\','
>
>>> ||'\''||rec.c2||'\')';
>
>
> If this case the query will be
> insert into test(c1,c2) values ('2004-02-13', 'Hai')
>
> If there is a null value encountered i will return an error for the
> following query
> insert into test(c1,c2) values ('NULL', 'Hai')
> ERROR: Bad timestamp external representation 'NULL'
It's because you can't use quotes with null. Valid query is:
insert into test(c1,c2) values (NULL, 'Hai');
Your dynamic query will then look like:
sqlstr := 'insert into test(c1, c2) values (' ||COALESCE('\'' || rec.c1
|| '\'','NULL') ...
or more elegant:
sqlstr := 'insert into test(c1, c2) values ('
||COALESCE(quote_literal(rec.c1),'NULL') ...
Regards,
Tomasz Myrta
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Cc: jasiek@klaster.net, sgnerd@yahoo.com.sg
Subject: Re: How to avoid nulls while writing string for dynamic query
In-Reply-To: <402C85B3.2020204@klaster.net>
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