Обсуждение: partial time stamp query

I am trying to write a query that grabs one particular day from a =
timestamp column. The data are ordered in 15 minute chunks like this:

2010-07-07 12:45:00
2010-07-07 13:00:00
2010-07-07 13:15:00
2010-07-07 13:30:00
etc=85

If I wanted all records from july 7th 2010, I would expect 4 x 24 =3D 96 =
records per day.

I have tried the '=3D' operator, like this=20

WHERE derived_tsoil_fifteen_min_stacked.time2 =3D '2010-07-07*'

but that grabs nothing, and using the '~' operator grabs everything with =
a 2010 or 07 in it=85 in other words all days from July of 2010.=20

Any suggestions would be much appreciated.=20

On Mon, Feb 4, 2013 at 9:45 AM, Kirk Wythers <kirk.wythers@gmail.com> wrote=
:

> I am trying to write a query that grabs one particular day from a
> timestamp column. The data are ordered in 15 minute chunks like this:
>
> 2010-07-07 12:45:00
> 2010-07-07 13:00:00
> 2010-07-07 13:15:00
> 2010-07-07 13:30:00
> etc=85
>
> WHERE derived_tsoil_fifteen_min_stacked.time2 =3D '2010-07-07*'
> but that grabs nothing


Just cast the timestamp to a date before you compare it:

WHERE derived_tsoil_fifteen_min_stacked.time2::date =3D '2010-07-07'

--=20
Moshe Jacobson
Nead Werx, Inc. | Manager of Systems Engineering
2323 Cumberland Parkway, Suite 201 | Atlanta, GA 30339
moshe@neadwerx.com | www.neadwerx.com

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