Re: select to_number('1,000', '999,999');

On Mon, 22 Nov 2004, Stephan Szabo wrote:

> On Mon, 22 Nov 2004, David Schweikert wrote:
>
> > On Sun, Nov 21, 2004 at 20:10:08 -0500, Tom Lane wrote:
> > > I'm not entirely convinced this is a bug. I get the right answer from
> > >
> > > regression=# select to_number('001,000', '999,999') ;
> > > to_number
> > > -----------
> > > 1000
> > > (1 row)
> > >
> > > It's arguable that to_number() should throw an error when the input
> > > doesn't match the format, but right now it doesn't ...
> >
> > It seems strange to me that to_char(1000,'999,999') works (it returns
> > 1,000), but the reverse doesn't.
> >
> > I want to convert a formatted number with group separators, but I don't
> > know how many digits it has: should I count the digits myself and adapt
> > the mask (which is a customization and thus entered by the user)?
>
> No, but I think you're supposed to use FM in such cases.
>
> select to_number(1000, 'FM999,999');

Of course, I don't think the fact that it does that is actually documented
in the 7.4 docs now that I look. I must have just run into it through
experimentation, so I wonder if that's actually intended behavior or not.