Re: how to generate a list of distinct scalar values from a column which type is array

From: "A(dot) Kretschmer" <andreas(dot)kretschmer(at)schollglas(dot)com>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: how to generate a list of distinct scalar values from a column which type is array
Date: 2007-02-22 13:34:33
Message-ID: 20070222133433.GF15488@a-kretschmer.de
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am Thu, dem 22.02.2007, um 14:25:36 +0100 mailte A. Kretschmer folgendes:
> test=*# select * from a;
> c
> -------------
> {aaa,bb,c}
> {dddd,eeee}
> {aaa,eeee}
> (3 rows)
>
>
> test=*# select distinct c[s] from a, generate_series(1,3)s where c[s] is not null;
> c
> ------
> aaa
> bb
> c
> dddd
> eeee
> (5 rows)
>
>
> You need to know the greatest upper dimension of the array, in this case
> 3, for the generate_series - function.

select distinct c[s] from a, generate_series(1,(select max(array_upper(c,1)) from a))s where c[s] is not null;

;-)

Andreas
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Andreas Kretschmer
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