Re: How to convert postgres timestamp to date: yyyy-mm-dd

Vivek Khera <vivek(at)khera(dot)org> writes:
> On Mar 11, 2008, at 2:50 PM, A. Kretschmer wrote:
>>>> i.e ... WHERE pt.created_date >= '2008-01-21'
>>
>> You can't compare a date or timestamp to a varchar or text. For your
>> example, cast the date-string to a real date like:

> Since which version of Pg?
> Queries like the above have worked for me from 7.3 up thru 8.1, which
> is my current production environment.

The above example is not in fact comparing to a varchar or text value.
It's comparing to an unknown-type literal constant, which will
preferentially be resolved as being the same type as the variable
it's being compared to.

Whether you can do a cross-data-type comparison between two variables of
known data types is a whole 'nother story. PG 8.3 insists on an
explicit cast in some cases where earlier versions silently did a
(possibly surprising) type conversion.

regards, tom lane