Re: Question on joining tables - Mailing list pgsql-novice

From Andrew McMillan
Subject Re: Question on joining tables
Date
Msg-id 1023139658.12576.42.camel@kant.mcmillan.net.nz
Whole thread Raw
In response to Question on joining tables  ("Chris Pizzo" <chris@artinside.com>)
List pgsql-novice
On Tue, 2002-06-04 at 05:06, Chris Pizzo wrote:
> Hi,
> I have an interesting issue where i need to join two tables where the field that jions them is similar but not
identical. Table A field data is char(12) and contains data that looks like: 
>
> BBB12345
> BBB345
> BBB4980
> BBB3455
>
> Table B field data is char(32) and contains data that looks like:
>
> MMM12345
> BBB345
> BBB4980
> MMM3455
>
> I need a way to equate  MMM12345 to BBB12345 in the join.  I tried using substrings but this fails ie.
>
> select some_data from A,B where (substr(A.field,4,12) = substr(B.field,4,12));
>
> anyone point me in the right direction?

Since you are using CHAR(NN) fields your values will be space padded.
This is probably what is causing the problem.

Try something like:

select some_data from A,B where (trim(substr(A.field,4,12)::TEXT) =
trim(substr(B.field,4,12)::TEXT));

Regards,
                    Andrew.

--
--------------------------------------------------------------------
Andrew @ Catalyst .Net.NZ Ltd, PO Box 11-053, Manners St, Wellington
WEB: http://catalyst.net.nz/        PHYS: Level 2, 150-154 Willis St
DDI: +64(4)916-7201    MOB: +64(21)635-694    OFFICE: +64(4)499-2267
       Are you enrolled at http://schoolreunions.co.nz/ yet?


pgsql-novice by date:

Previous
From: Tom Ansley
Date:
Subject: JDBC issue
Next
From: "Colin Mangiagalli"
Date:
Subject: Incorrect date/time returned by current_timestamp