Re: FM format modifier does not remove leading zero from year

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Guy Rouillier <guyr-ml1@burntmail.com>
Cc: pgsql-general@postgresql.org
Date: 2010-01-06T20:29:05Z
Lists: pgsql-hackers, pgsql-general
Guy Rouillier <guyr-ml1@burntmail.com> writes:
> Oracle states clearly in the SQL Reference manual:

> "A modifier can appear in a format model more than once. In such a case, 
> each subsequent occurrence toggles the effects of the modifier."

*Toggles* the effect of the modifier?  Egad, what drunken idiot chose
that specification?

That's certainly not how PG is interpreting the FM modifier --- we
suppose it applies to just the specifier it's attached to.  Still,
we generally assume that Oracle is the authoritative reference for
how to_char() ought to behave, so maybe we should hold our noses
and change it.  Problem is that this would inevitably break
practically every existing use of to_date with FM :-( (not to mention
the other modifiers, which I suppose behave that way too?)

Anyway, your example clearly shows that FM ought to strip leading
zeroes in YY, so that change ought to get made.

			regards, tom lane