Re: NEWBEE: 'WHERE true' question

From: GH <grasshacker(at)over-yonder(dot)net>
To:
Cc: PGSQL Novice List <pgsql-novice(at)postgresql(dot)org>
Subject: Re: NEWBEE: 'WHERE true' question
Date: 2000-11-16 04:36:58
Message-ID: 20001115223658.A13873@over-yonder.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-novice

On Wed, Nov 15, 2000 at 09:16:37PM -0700, some SMTP stream spewed forth:
> Hello,
>
*snip*
> A snippet from this code is as follows:
>
> ...
> $where = 'true';
> if ($form->{number}) {
> $callback .= "&number=$form->{number}";
> $where .= " AND number ~* '$form->{number}'";
> }
> if ($form->{description}) {
> $callback .= "&description=$form->{description}";
> $where .= " AND description ~* '$form->{description}'";
> }
>
> $query = qq|SELECT id, number, description, onhand, unit, sellprice
> FROM parts
> WHERE $where
> ORDER BY $form->{sort}
> |;
> ...
>
> Now if the two 'if' conditionals are false, the query becomes:
>
> SELECT id, number, description, onhand, unit, sellprice
> FROM parts
> WHERE true
> ORDER BY number
>
>
> What does it mean here for the WHERE to be true? What is being tested
> for true? Is this just a 'place holder', if you will, for the WHERE
> field in case the two 'if' conditionals are false and so the WHERE field
> is not blank?
>

Er, I hope this helps.
< http://www.postgresql.org/docs/user/sql-select.htm#SQL-WHERE >

It looks like the 'true' is just in there to ensure that all rows are
returned.
I can't think of why someone wolud do that..

G'luck and
cheers
gh

> Thanks,
> Murrah Boswell
>

In response to

Browse pgsql-novice by date

  From Date Subject
Next Message Tom Lane 2000-11-16 04:44:44 Re: Granting Browser Access to pgsql database.
Previous Message OTR Comm 2000-11-16 04:16:37 NEWBEE: 'WHERE true' question