Thread: Significant spaces

PostGreSQL 7.2.4

Can anyone tell me where trailing spaces are significant in CHAR, VARCHAR and TEXT fields?

We pass a VARCHAR variable into a 3rd party language product 'function' as a CHAR(250). The CHAR(250) field is then used to interrogate a table to see if that value exists. If not, a row with that value is inserted into the table as a VARCHAR(N). The issue is that the value when inserted into the VARCHAR in the table appears to carry trailing spaces, so when a subsequent lookup is performed with the same value, the value is not 'found' and a further insert occurs.
The problem appears to disappear if I change the definition of the passed parameter to a VARCHAR as well.
Is this a known issue?

Regards, Steve Tucknott ReTSol Ltd DDI: 01903 828769

The char data type will automatically pad unused positions with space so
it stays fixed at 250.

Varchar will automatically trim any unused positions.

I assume in your code somewhere you are doing a CAST(char column as
varchar).  You can enclose this in a TRIM to remove whitespace at
beginning and end.  TRIM(CAST(char column as varchar))

HTH
On Fri, 2004-07-30 at 07:35, Steve Tucknott wrote:
> PostGreSQL 7.2.4
>
> Can anyone tell me where trailing spaces are significant in CHAR,
> VARCHAR and TEXT fields?
>
> We pass a VARCHAR variable into a 3rd party language product
> 'function' as a CHAR(250). The CHAR(250) field is then used to
> interrogate a table to see if that value exists. If not, a row with
> that value is inserted into the table as a VARCHAR(N). The issue is
> that the value when inserted into the VARCHAR in the table appears to
> carry trailing spaces, so when a subsequent lookup is performed with
> the same value, the value is not 'found' and a further insert occurs.
> The problem appears to disappear if I change the definition of the
> passed parameter to a VARCHAR as well.
> Is this a known issue?
>
>
> Regards,
>
> Steve Tucknott
>
> ReTSol Ltd
>
> DDI: 01903 828769

At 12:12 AM 7/31/04, mike g wrote:
>Varchar will automatically trim any unused positions.


varchar doesn't 'trim' anything - it inserts text exactly as it is coded.


fbax=# create table vctest( c1 varchar );
CREATE
fbax=# insert into vctest values('abc   ');
INSERT 11939819 1
fbax=# insert into vctest values('abcd');
INSERT 11939820 1
fbax=# select *,length(c1) from vctest where c1~' $';
    c1   | length
--------+--------
  abc    |      6
(1 row)