[lug] postgresql query question

[D. Stimits]

George Sexton wrote:
> Is there something that converts the timestamp to seconds? If so, can 
> you do:
> 
> (convert_to_seconds(date_field) modulo 60) = 0
> 
> Nick Golder wrote:
> 
>> Is there a way to query data between two timestamps based on some
>> selected interval?  For example, I want to query all data for every 60
>> second interval between 2004-09-10 14:00:00 and 2004-10-10 14:00:00.
>> I looked at 'INTERVAL' but that appears to only show it for the first
>> interval after a selected timestamp. 
>> TIA,
>>
> 

Functions can be viewed in psql via:
\df

Using \df '*now*' shows much.

Try:

SELECT now() - CAST('1 seconds' AS INTERVAL);

The problem with the modulus is that it wants to operate on integers or 
numeric types...timestamps don't qualify.

D. Stimits, stimits AT comcast DOT net