Thread: Range of caracters

On þri, 2007-08-07 at 10:07 -0700, Wilton Wonrath wrote:

>     Data Table
> 
> Inicial                              -------------  Final
> 9C2HB02107R008000                         9C2HB02107R008200
>     
> FAIXA1                                                FAIXA100
> 
> I´m doing the following query:
> 
> SELECT recallfxchassi.* FROM recallfxchassi 
> LEFT JOIN recall ON recallfxchassi.idrecall = recall.id WHERE 
> ('FAIXA2' BETWEEN chassiinicial AND chassifinal);
> 
> This is not returning anything. I believe that is because it´s check´s
> caracter by caracter and 2 is bigger than 1. But in a real situation
> I will need that return something (FAIXA2 is between FAIXA1 and
> FAIXA100).
> 
> Does anyone knows if exists some way or command in PostgreSQL that
> could solve this "problem" ?

sounds like you need to normalize your schema, but it is possible.

if the prefix is fixed then you can do 
WHERE substr('FAIXA2',6)::integer      between substr(chassiinicial,6)::integer      and
substr(chassifinal,6)::integer;


if the prefix is not fixed, but it's length is, and you are using a
sufficiently recent version of postgresql, you can do:
WHERE (substr('FAIXA2',1,5),      substr('FAIXA2',6)::integer)   between          (substr(chassiinicial,1,5),
substr(chassiinicial,6)::integer)  and (substr(chassifinal,1,5),       substr(chassifinal,6)::integer);
 

if the prefix length is not fixed, you will have
to do some juggling:
WHERE (substring('FAIXA2' from '^[^0-9]*'),      substring('FAIXA2' from '[0-9]+$')::integer)   between
(substr(chassiinicialfrom '^[^0-9]*'),       substr(chassiinicial from '[0-9]+$')::integer)   and (substr(chassifinal
from'^[^0-9]*'),       substr(chassifinal from '[0-9]+$')::integer);
 


gnari