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* UPDATE with a SELECT and subSELECT(About comparing dates and non dates data)
@ 2002-12-16 18:57 javier garcia <andresjavier.garcia@wanadoo.es>
0 siblings, 0 replies; 4+ messages in thread
From: javier garcia @ 2002-12-16 18:57 UTC (permalink / raw)
To: pgsql-sql
Thanks Josh and Bret for your answers.
But I think I can try a slightly different thing. As I said, I've got data,
extracted from rain gauge stations. Perhaps I wasn't explicit enough. My
source data are in this format:
cod_variable | cod_station | year | month | ten | rain_day1 | wind_day1 |
rain_day2 | wind_day2 | rain_day3 | wind_day3 | rain_day4 | wind_day4 |
rain_day5 | wind_day5 | rain_day6 | wind_day6 | rain_day7 | wind_day7 |
rain_day8 | wind_day8 | rain_day9 | wind_day9 | rain_day10 | wind_day10 |
rain_day11 | wind_day11 | ten_sum_rain
--------------+-------------+------+-------+-----+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+------
30201 | 7237 | 1953 | 1 | 1 | 0 | 0 |
0 | 0 | 0 | 0 | 0 | 0 |
0 | 0 | 0 | 0 | 0 | 0 |
0 | 0 | 0 | 0 | 0 | 0 |
| | 0
and this is just a row (ten means that the data belong to the first, second
or third of the weeks of the month). I've got five gauge stations and daily
data for about forty years (73000 of these long rows). Missing data are
non-existent rows; so, when a row doesn't appears I lost ten rain data (the
rain of ten days).
But with the help of the wonderful people in this list I could extract rain
series (excellent):
cod_station | year | month | day | rain
-------------+------+-------+-----+------
7250 | 1933 | 8 | 1 | 0
7250 | 1933 | 8 | 2 | 0
7250 | 1933 | 8 | 3 | 0...
So, now, in the result of this query, a missing data translates into several
non-existent row.
Now, I have prepared a table with a complete series of date field (everyday
from 1553 to 2004), and made ALTER it to ADD aditional fields for every
station I have:
year | month | day | st7237 | st7238 | st7239 ...
------+-------+-----+---------+---------+---------+---------
1953 | 1 | 1 | | | |
1953 | 1 | 2 | | | |
1953 | 1 | 3 | | | |...
My problem is that I need to fill in the gaps (the available rain data in the
corresponding stations), and this would be a very good output for me.
I've prepared an UPDATE but it doesn't work. Perhaps someone could tell me
where is the error (I've not a very good knowledge of Postgresql). The UPDATE
is based on the results of the query:
----------------------------------------------------------------------------
UPDATE series_lluvia SET st7237=rain FROM
/* here begins the SELECT to obtain the series for one rain gauge station;
and it works right
from here to the next comment */
SELECT cod_station, year, month, day, rain FROM (
SELECT cod_variable, cod_station, year, month, 1 as day, rain_day1 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 2 as day, rain_day2 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 3 as day, rain_day3 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 4 as day, rain_day4 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 5 as day, rain_day5 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 6 as day, rain_day6 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 7 as day, rain_day7 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 8 as day, rain_day8 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 9 as day, rain_day9 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 10 as day, rain_day10 as rain
FROM pluviometria WHERE ten=1
UNION ALL
SELECT cod_variable, cod_station, year, month, 11 as day, rain_day1 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 12 as day, rain_day2 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 13 as day, rain_day3 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 14 as day, rain_day4 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 15 as day, rain_day5 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 16 as day, rain_day6 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 17 as day, rain_day7 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 18 as day, rain_day8 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 19 as day, rain_day9 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 20 as day, rain_day10 as rain
FROM pluviometria WHERE ten=2
UNION ALL
SELECT cod_variable, cod_station, year, month, 21 as day, rain_day1 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 22 as day, rain_day2 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 23 as day, rain_day3 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 24 as day, rain_day4 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 25 as day, rain_day5 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 26 as day, rain_day6 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 27 as day, rain_day7 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 28 as day, rain_day8 as rain
FROM pluviometria WHERE ten=3
UNION ALL
SELECT cod_variable, cod_station, year, month, 29 as day, rain_day9 as rain
FROM pluviometria WHERE ten=3 AND rain_day9 IS NOT NULL
UNION ALL
SELECT cod_variable, cod_station, year, month, 30 as day, rain_day10 as rain
FROM pluviometria WHERE ten=3 AND rain_day10 IS NOT NULL
UNION ALL
SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11 as rain
FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
ORDER BY cod_station, year, month, day) AS temp WHERE cod_station=7238
/* the SELECT has finished here */
WHERE series_lluvia.year=temp.year AND series_lluvia.month=temp.month AND
series_lluvia.day=temp.day;
-------------------------------------------------------------------
Please can you tell me if the syntax of this UPDATE is correct? (Can I use
the results of a SELECT to UPDATE a table?)
Thanks for your help. I know this is too long.
Regards,
Javier
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: UPDATE with a SELECT and subSELECT(About comparing dates and non dates data)
@ 2002-12-17 09:34 Christoph Haller <ch@rodos.fzk.de>
0 siblings, 1 reply; 4+ messages in thread
From: Christoph Haller @ 2002-12-17 09:34 UTC (permalink / raw)
To: andresjavier.garcia@wanadoo.es; +Cc: pgsql-sql
> My problem is that I need to fill in the gaps (the available rain data
in the
> corresponding stations), and this would be a very good output for me.
> I've prepared an UPDATE but it doesn't work. Perhaps someone could
tell me
> where is the error (I've not a very good knowledge of Postgresql). The
UPDATE
> is based on the results of the query:
>
>
----------------------------------------------------------------------------
> UPDATE series_lluvia SET st7237=rain FROM
>
> /* here begins the SELECT to obtain the series for one rain gauge
station;
> and it works right
> from here to the next comment */
> SELECT cod_station, year, month, day, rain FROM (
>
> SELECT cod_variable, cod_station, year, month, 1 as day, rain_day1 as
rain
> FROM pluviometria WHERE ten=1
> UNION ALL
> ...
> SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11
as rain
> FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
> ORDER BY cod_station, year, month, day) AS temp WHERE cod_station=7238
>
> /* the SELECT has finished here */
> WHERE series_lluvia.year=temp.year AND series_lluvia.month=temp.month
AND
> series_lluvia.day=temp.day;
> -------------------------------------------------------------------
>
> Please can you tell me if the syntax of this UPDATE is correct? (Can I
use
> the results of a SELECT to UPDATE a table?)
>
Javier,
I've seen something similar on the list in January this year.
Maybe it works. Try
UPDATE series_lluvia SET st7237=(
SELECT rain FROM (
SELECT cod_variable, cod_station, year, month, 1 as day, rain_day1 as
rain
FROM pluviometria WHERE ten=1
UNION ALL
...
SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11 as
rain
FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
ORDER BY cod_station, year, month, day) AS temp WHERE cod_station=7238
)
WHERE series_lluvia.year=temp.year AND series_lluvia.month=temp.month
AND
series_lluvia.day=temp.day;
Regards, Christoph
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: UPDATE with a SELECT and subSELECT(About comparing dates and non dates data)
@ 2002-12-19 16:16 javier garcia <andresjavier.garcia@wanadoo.es>
parent: Christoph Haller <ch@rodos.fzk.de>
0 siblings, 0 replies; 4+ messages in thread
From: javier garcia @ 2002-12-19 16:16 UTC (permalink / raw)
To: Christoph Haller <ch@rodos.fzk.de>; +Cc: pgsql-sql
Thanks Christoph;
Typing what you told me there was an errror; I' ve changed it slightly an it
seems that this sintax is correct. I say "it seems" because the computer
begins to process the query but doesn't finish it. I've leaved it working for
more than half an hour, before cancel it, with no result.
Thank you anyway. This is what I think is a good sintax for UPDATE - SELECT -
SUBSELECT. Perhaps in mor simple cases it works. May someone is interested in
it.
----------
Javier
--------------------------------------------------------------------
UPDATE series_lluvia SET st7237=(
SELECT rain FROM (
SELECT cod_variable, cod_station, year, month, 1 as day, rain_day1 as
rain
FROM pluviometria WHERE ten=1
UNION ALL
...
SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11 as
rain
FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
ORDER BY cod_station, year, month, day) AS temp WHERE cod_station=7237) AS
temp2 WHERE series_lluvia.year=temp2.year AND
series_lluvia.month=temp2.month AND series_lluvia.day=temp2.day);
------------------------------------------------------
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: UPDATE with a SELECT and subSELECT(About comparing dates and non dates data)
@ 2002-12-20 10:22 Christoph Haller <ch@rodos.fzk.de>
0 siblings, 0 replies; 4+ messages in thread
From: Christoph Haller @ 2002-12-20 10:22 UTC (permalink / raw)
To: andresjavier.garcia@wanadoo.es; +Cc: pgsql-sql
>
> Typing what you told me there was an errror; I' ve changed it slightly
an it
> seems that this sintax is correct. I say "it seems" because the
computer
> begins to process the query but doesn't finish it. I've leaved it
working for
> more than half an hour, before cancel it, with no result.
>
> Thank you anyway. This is what I think is a good sintax for UPDATE -
SELECT -
> SUBSELECT. Perhaps in mor simple cases it works. May someone is
interested in
> it.
>
> ----------
> Javier
>
> --------------------------------------------------------------------
> UPDATE series_lluvia SET st7237=(
> SELECT rain FROM (
> SELECT cod_variable, cod_station, year, month, 1 as day, rain_day1 as
> rain
> FROM pluviometria WHERE ten=1
> UNION ALL
> ...
> SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11
as
> rain
> FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
> ORDER BY cod_station, year, month, day) AS temp WHERE
cod_station=7237) AS
> temp2 WHERE series_lluvia.year=temp2.year AND
> series_lluvia.month=temp2.month AND series_lluvia.day=temp2.day);
> ------------------------------------------------------
>
Javier,
I've seen several queries which seemed to run for ages before.
In many cases it helped to generate temporary tables and / or
split up into "smaller" commands.
Have you tried it by removing the union clauses as
UPDATE series_lluvia SET st7237=(
SELECT rain FROM (
SELECT cod_variable, cod_station, year, month, 31 as day, rain_day11
as
rain
FROM pluviometria WHERE ten=3 AND rain_day11 IS NOT NULL
ORDER BY cod_station, year, month, day) AS temp WHERE cod_station=7237)
AS
temp2 WHERE series_lluvia.year=temp2.year AND
series_lluvia.month=temp2.month AND series_lluvia.day=temp2.day);
If this runs in an acceptable time, split up into several UPDATEs.
If not, think of using temporary tables for SELECT - SUBSELECT.
It's probably useful to do this in a transaction block started by BEGIN;
so you can ROLLBACK; if the result is wrong.
Regards, Christoph
^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2002-12-20 10:22 UTC | newest]
Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2002-12-16 18:57 UPDATE with a SELECT and subSELECT(About comparing dates and non dates data) javier garcia <andresjavier.garcia@wanadoo.es>
2002-12-17 09:34 Re: UPDATE with a SELECT and subSELECT(About comparing dates and non dates data) Christoph Haller <ch@rodos.fzk.de>
2002-12-19 16:16 ` javier garcia <andresjavier.garcia@wanadoo.es>
2002-12-20 10:22 Re: UPDATE with a SELECT and subSELECT(About comparing dates and non dates data) Christoph Haller <ch@rodos.fzk.de>
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