Re: '_' < '5' -- different answer on 7.2 and 7.3

David Blasby <dblasby@refractions.net>

From: David Blasby <dblasby@refractions.net>
To: Stephan Szabo <sszabo@megazone23.bigpanda.com>, pgsql-hackers@postgresql.org
Date: 2003-07-04T23:00:40Z
Lists: pgsql-hackers
> My first guess would be that you're not running in "C" locale
> on the 7.3 system.  I get false on my 7.3.1 system in C locale,
> but if I compare the two strings in C using en_US for example I
> seem to get results like the above ('_'<'5' is true).

It turns out our 7.3 database was somehow initd with local "en_US".

I'm trying to get postgresql and a MS vc++ to communicate.

In postgresql 7.3 (en_US):

toponymy=# select '_' < '5';;
  ?column?
----------
  t
(1 row)


toponymy=# select '_5' < '5';
  ?column?
----------
  f
(1 row)


But in MS vc++:

	TRACE("locale set to 'en_US'\n");
	setlocale( LC_ALL, "English_United States" );
	if (strcoll("_5","5") <0 )
		TRACE("strcoll('_5','5') --  <0 \n");
	else
		TRACE( "strcoll('_5','5') -- >=0\n");

returns:
locale set to 'en_US'
strcoll('_5','5') --  <0


Which is to say postgresql thinks "_5" > "5", but
(a bit strangely) "_" < "5" (the '>' and '<' are reversed).

vc++ thinks "_5" < "5" and "_" < "5".

So, which one is correct and why does the other disagree?

dave