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
> my data are structured in three integer fields, and as a result of a query I
> 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
> ...
> and this for several rain station for about forty years. My problem is that
I
> need to find missing data (a missing data here is a non-existent row).
>
> I think I could prepare a table with a complete series of date field, and
> ALTER it to ADD aditional fields for every station I need to add:
>
> date | stat_7250 | stat_7237 ...
> ----------------+--------------------+---------------+------...
> 1/11/1999
> 2/12/1999
> ...
> , and make an UPDATE that in someway, will compare the "date" of this table
> with an extracted date from "year", "day" and "rain" from the aforementioned
> SELECT, leaving the non-coincident dates in blank and filling the rain data
> 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
little confused as to what you consider a "missing" date. Could you be more
explicit?
--
-Josh Berkus
Aglio Database Solutions
San Francisco
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