Thread: Bug fix for missing years in make_date()

Folks,

For reasons unclear, dates before the Common Era are disallowed in
make_date(), even though about 2/3 of the underlying data type's range
up until the present time fits that description.

Please find attached a patch fixing same.

Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
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On 3/26/15 5:26 PM, David Fetter wrote:
> +     * Note: Non-positive years are take to be BCE.

s/take/taken/
-- 
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com

On Mon, Mar 30, 2015 at 05:35:29PM -0500, Jim Nasby wrote:
> On 3/26/15 5:26 PM, David Fetter wrote:
> >+     * Note: Non-positive years are take to be BCE.
>
> s/take/taken/

Good point.  Next patch attached.

Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
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On Tue, Mar 31, 2015 at 10:34:45AM -0400, Adam Brightwell wrote:
> >
> > Good point.  Next patch attached.
> 
> 
>   /*
> - * Note: we'll reject zero or negative year values.  Perhaps negatives
> - * should be allowed to represent BC years?
> + * Note: Non-positive years are taken to be BCE.
>   */
> 
> Previously, zero was rejected, what does it do now? I'm sure it represents
> 0 AD/CE, however, is that important enough to note given that it was not
> allowed previously?

Now, it's supposed to take 0 as 1 BCE, -1 as 2 BCE, etc.  There should
probably be tests for that. The issue here is that zero was
popularized a very long time after the beginning of the Common Era.

Cheers,
David.
-- 
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
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David Fetter <david@fetter.org> writes:
> On Tue, Mar 31, 2015 at 10:34:45AM -0400, Adam Brightwell wrote:
>> Previously, zero was rejected, what does it do now? I'm sure it represents
>> 0 AD/CE, however, is that important enough to note given that it was not
>> allowed previously?

> Now, it's supposed to take 0 as 1 BCE, -1 as 2 BCE, etc.  There should
> probably be tests for that.

Surely that is *not* what we want?  I'd expect any user-facing date
function to reject zero and take -1 as 1 BC, etc.  The behavior you
describe is an internal convention, not something we want to expose
to users.
        regards, tom lane

On Tue, Mar 31, 2015 at 12:58:27PM -0400, Tom Lane wrote:
> David Fetter <david@fetter.org> writes:
> > On Tue, Mar 31, 2015 at 10:34:45AM -0400, Adam Brightwell wrote:
> >> Previously, zero was rejected, what does it do now? I'm sure it
> >> represents 0 AD/CE, however, is that important enough to note
> >> given that it was not allowed previously?
> 
> > Now, it's supposed to take 0 as 1 BCE, -1 as 2 BCE, etc.  There
> > should probably be tests for that.
> 
> Surely that is *not* what we want?

It is if we're to be consistent with the rest of the system, to wit:

SELECT to_date('YYYY','0000');   to_date    
---------------0001-01-01 BC
(1 row)

> I'd expect any user-facing date function to reject zero and take -1
> as 1 BC, etc.  The behavior you describe is an internal convention,
> not something we want to expose to users.

That ship has already sailed.

Cheers,
David.
-- 
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
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On Tue, Mar 31, 2015 at 12:22:39PM -0700, David Fetter wrote:
> On Tue, Mar 31, 2015 at 12:58:27PM -0400, Tom Lane wrote:
> > David Fetter <david@fetter.org> writes:
> > > On Tue, Mar 31, 2015 at 10:34:45AM -0400, Adam Brightwell wrote:
> > >> Previously, zero was rejected, what does it do now? I'm sure it
> > >> represents 0 AD/CE, however, is that important enough to note
> > >> given that it was not allowed previously?
> >
> > > Now, it's supposed to take 0 as 1 BCE, -1 as 2 BCE, etc.  There
> > > should probably be tests for that.
> >
> > Surely that is *not* what we want?
>
> It is if we're to be consistent with the rest of the system, to wit:
>
> SELECT to_date('YYYY','0000');
>     to_date
> ---------------
>  0001-01-01 BC
> (1 row)

Looking at this further, I think that it should be consistent with
cast rather than with to_date().

SELECT date '0000-01-01';
ERROR:  date/time field value out of range: "0000-01-01"
LINE 1: SELECT date '0000-01-01';

Please find attached the next revision of the patch.

Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
Phone: +1 415 235 3778  AIM: dfetter666  Yahoo!: dfetter
Skype: davidfetter      XMPP: david.fetter@gmail.com

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