Re: Abfrage mit Datum als Serie.

Thomas Drebert <[email protected]> Thu, 13 Mar 2014 06:04:14 +0100
Newsgroups gmane.comp.db.postgresql.german
Message-ID <CANn+32iPN5Qhyne0UkA2LO9PiyFM0bXdSvU3emAH2pM4BE+evA@mail.gmail.com>
Hallo,

leider habe ich wieder das Problem die Daten zusammen zu führen.
select * from variablen order by 1

funktioniert
Die Tabelle
select (current_date + s * '1day'::interval)::date as d from
generate_Series(1,10)s

Funktioniert auch.

aber bei
select foo.d, variablen.value from (select (current_date + s *
'1day'::interval)::date as d from generate_Series(1,10)s) foo left join
variablen using(d) order by 1

bekomme ich die Fehlermeldung:
ERROR:  column "d" specified in USING clause does not exist in right table
********** Fehler **********

ERROR: column "d" specified in USING clause does not exist in right table
SQL Status:42703

Schöne Grüße
Thomas


2014-03-12 20:32 GMT+01:00 Andreas Kretschmer <[email protected]>:

> Thomas Drebert <[email protected]> wrote:
>
> > Vielleicht kann mir jemand helfen, wie ich das verbinden kann.
>
>
> Einfaches Besipiel, Du hast:
>
> ,----
> | test=*# select * from messung order by 1;
> |      d      | val
> | ------------+-----
> |  2014-03-12 |   9
> |  2014-03-13 |   5
> |  2014-03-15 |   7
> |  2014-03-16 |   2
> |  2014-03-17 |   7
> |  2014-03-17 |   5
> |  2014-03-17 |  10
> |  2014-03-17 |   6
> |  2014-03-19 |   5
> |  2014-03-21 |   6
> | (10 rows)
> `----
>
> Auf die einzelnen Tage via generate_series():
>
> ,----
> | test=*# select foo.d, messung.val from (select (current_date + s *
> '1day'::interval)::date as d from generate_Series(1,10)s) foo left join
> messung using(d) order by 1;
> |      d      | val
> | ------------+-----
> |  2014-03-13 |   5
> |  2014-03-14 |
> |  2014-03-15 |   7
> |  2014-03-16 |   2
> |  2014-03-17 |   7
> |  2014-03-17 |   5
> |  2014-03-17 |  10
> |  2014-03-17 |   6
> |  2014-03-18 |
> |  2014-03-19 |   5
> |  2014-03-20 |
> |  2014-03-21 |   6
> |  2014-03-22 |
> | (13 rows)
> `----
>
>
> Und nun aggregieren, z.B. avg():
>
> ,----
> | test=*# select foo.d, avg(messung.val) from (select (current_date + s *
> '1day'::interval)::date as d from generate_Series(1,10)s) foo left join
> messung using(d) group by 1 order by 1;
> |      d      |        avg
> | ------------+--------------------
> |  2014-03-13 | 5.0000000000000000
> |  2014-03-14 |
> |  2014-03-15 | 7.0000000000000000
> |  2014-03-16 | 2.0000000000000000
> |  2014-03-17 | 7.0000000000000000
> |  2014-03-18 |
> |  2014-03-19 | 5.0000000000000000
> |  2014-03-20 |
> |  2014-03-21 | 6.0000000000000000
> |  2014-03-22 |
> | (10 rows)
> `----
>
>
> Du baust Dir halt via :
>
> ,----
> | test=*# select (current_date + s * '1day'::interval)::date as d from
> generate_Series(1,10)s;
> |      d
> | ------------
> |  2014-03-13
> |  2014-03-14
> |  2014-03-15
> |  2014-03-16
> |  2014-03-17
> |  2014-03-18
> |  2014-03-19
> |  2014-03-20
> |  2014-03-21
> |  2014-03-22
> | (10 rows)
> `----
>
> eine Hilfstabelle, die ALLE Tagen enthält, und nutzt das als Basis für die
> weitere Arbeit.
>
> Mit generate_series() warst Du ja schon auf dem richtigen Weg ;-)
> Viel Erfolg noch!
>
>
> Andreas
> --
> Really, I'm not out to destroy Microsoft. That will just be a completely
> unintentional side effect.                              (Linus Torvalds)
> "If I was god, I would recompile penguin with --enable-fly."   (unknown)
> Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°
>
>
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