Re: The same result for with SPACE and without SPACE

Hello Scott and all,

Here the question comes with respect to CHAR(10) to CHARACTeR VARYING( 10 ) comparison results.
char_10 - type character ( 10 )
var_char_10 - type character varying ( 10)

When I do the comparison between char_10 and var_char_10 columns, I may get the wrong results.
var_char_10 is always trimmed from right.
char_10 has padded data of blank or spaces.
Now I compare char10 and var_char_10 columns, I will get the wrong results because char​_10 has padded spaces.

Is that correct or will it ignore whitespaces at the end of char_10 column?

Thanks,
Sarwar

________________________________
From: Scott Ribe <scott_ribe(at)elevated-dev(dot)com>
Sent: Thursday, June 15, 2023 11:56 AM
To: Wetmore, Matthew (CTR) <Matthew(dot)Wetmore(at)express-scripts(dot)com>
Cc: mahesh <mahesha_dba(at)yahoo(dot)com>; Mohammed Aslam <hmdaslam97(at)gmail(dot)com>; pgsql-admin(at)lists(dot)postgresql(dot)org <pgsql-admin(at)lists(dot)postgresql(dot)org>; Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>; M Sarwar <sarwarmd02(at)outlook(dot)com>
Subject: Re: The same result for with SPACE and without SPACE

Nobody's kicking you out of any group. Someone requested themselves to be removed, with a typo that made it ambiguous.

The original question had nothing to do with INT, it was behavior of CHAR and trailing spaces.

> select c1 from matt_test where c1 = '123'
> -- all 3 rows returned.
> Is it expected behavior that all 3 rows would be returned (because the space isn’t an INT?)

Yes. Or more precisely, it is because when a string is cast to an int, leading and trailing spaces are ignored. The alternative would be to raise an error, as 'an integer plus some spaces' is not an integer...

> select c2 from matt_test2 where c2 = '123'
> -- 1 rows returned.

Yes, for TEXT column, which behaves the same as VARCHAR. Also 1 row for:

select c2 from matt_test2 where c2 = '123 '

But 2 rows returned for CHAR column, as inserting '123' and '123 ' into CHAR(n) results in the same value being inserted. And also 2 rows returned for:

select c2 from matt_test2 where c2 = '123 '

^^^ which was the original question