Re: weird situation, BUG or I'm not doing it right - Mailing list pgsql-sql

From Michael Paesold
Subject Re: weird situation, BUG or I'm not doing it right
Date
Msg-id 002201c24c35$d5bd0ef0$0100a8c0@beeblebrox
Whole thread Raw
In response to weird situation, BUG or I'm not doing it right  (Jiaqing Wang <jjw72@swbell.net>)
Responses Re: weird situation, BUG or I'm not doing it right  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-sql
Ross J. Reedstrom wrote:

> On Sat, Aug 24, 2002 at 10:56:31PM -0700, Jiaqing Wang wrote:
> > Hello,
> >
> > I found below situation weird, it seems to me a bug.
> >
> > backend=> select * from valid_addr where state_abrev=upper('pr');
> >  zip_code | city_name | state_abrev
> > ----------+-----------+-------------
> > (0 rows)
> >
> > while "select * from valid_addr where state_abrev='PR';" produces
following
> > output
> >
> <20 lines of output>
>
> You left out the critical piece: what's the schema for the table
valid_addr?
> I'll deduce that the column "state_abrev" is defined as something like
> 'char(4)'. It needs to be either char(2) (if _all_ state abbreviations are
> guarenteed to be only 2) or as text. fixed with char fields are padded
with
> blanks. Not a bug, but an feature of the SQL standard.
>
> Ross

Then, why is 'PR' blank padded to char(?) and upper('pr') not?
It seems that when comparing char with text, the comparision is done
as text, not as bpchar.

billing=# select 'A'::char(2) = upper('a');?column?
----------f

billing=# select 'A'::char(2) = upper('a')::bpchar;?column?
----------t


Regards,
Michael Paesold



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