Re: Quetions on Joins - Mailing list pgsql-general

From Ron Johnson
Subject Re: Quetions on Joins
Date
Msg-id 1062358157.7341.30.camel@haggis
Whole thread Raw
In response to Quetions on Joins  (Alex <alex@meerkatsoft.com>)
Responses Re: Quetions on Joins  (Alex <alex@meerkatsoft.com>)
List pgsql-general
On Sun, 2003-08-31 at 11:56, Alex wrote:
> Hi,
>
> I have a query where I want to filter out records from table_a if a
> field in table_a matches in table table_b. Basically table_b defines the
> filter.
>
> If table_b however is empty i dont get any results
>
> SELECT A.value_one FROM table_a AS A, table_b AS B WHERE  A.value_two <>
> B.value_two;
> or
> SELECT A.value_one FROM table_a AS A, table_b AS B WHERE  A.value_two <>
> B.value_two AND B.value_two NOTNULL;
>
> Only work if the there is a value in table_b.
> Could anyone tell me if there is a way to do that ?

If the filter is empty, how can you filter anything?

> PS: I'd like to thank here persons who reply rather than sending the
> message per mail.

What does that mean?

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

"they love our milk and honey, but preach about another way of living"
Merle Haggard, "The Fighting Side Of Me"


pgsql-general by date:

Previous
From: Ron Johnson
Date:
Subject: Re: About GPL and proprietary software
Next
From: Peter Eisentraut
Date:
Subject: Re: About GPL and proprietary software