Thread: Question on joining tables

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.

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