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From: Josh Berkus <josh@agliodbs.com>
Reply-To: josh@agliodbs.com
Organization: Aglio Database Solutions
To: javier garcia <andresjavier.garcia@wanadoo.es>,
	"pgsql-sql@postgresql.org" <pgsql-sql@postgresql.org>
Subject: Re: UPDATE comparing dates and non-dates data
Date: Fri, 13 Dec 2002 12:56:31 -0800
References: <200212131738.gBDHcCQ28797@natura.cebas.csic.es>
In-Reply-To: <200212131738.gBDHcCQ28797@natura.cebas.csic.es>
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Message-Id: <200212131256.31574.josh@agliodbs.com>

On Friday 13 December 2002 09:43, javier garcia wrote:
> Hi;
> I've got date data, extracted from rain gauge stations. The date of a row=
 in=20
> my data are structured in three integer fields, and as a result of a quer=
y I=20
> can get the following (what is quite good for my):
>  cod_station | year | month | day | rain
> -------------+------+-------+-----+------
>  7250        | 1933 |     8 |   1 |    45
>  7250        | 1933 |     8 |   2 |    3
>  7250        | 1933 |     8 |   3 |    0
> ...=20
> and this for several rain station for about forty years. My problem is th=
at=20
I=20
> need to find missing data (a missing data here is a non-existent row).
>=20
> I think I could prepare a table with a complete series of date field, and=
=20
> ALTER it to ADD aditional fields for every station I need to add:
>=20
>  date         |  stat_7250   | stat_7237 ...
> ----------------+--------------------+---------------+------...
> 1/11/1999
> 2/12/1999
> ...
> , and make an UPDATE that in someway, will compare the "date" of this tab=
le=20
> with an extracted date from "year", "day" and "rain" from the aforementio=
ned=20
> SELECT, leaving the non-coincident dates in blank and filling the rain da=
ta=20
> of the coincident dates. Is this possible? How?

I don't think this is the best method to find missing dates.  However, I'm =
 a=20
little confused as to what you consider a "missing" date.  Could you be mor=
e=20
explicit?


--=20
-Josh Berkus
 Aglio Database Solutions
 San Francisco