RE: Distinct Values

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От Hartwig Jens
Тема RE: Distinct Values
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Msg-id 819FEEAC94E6DC459F1FDC83C0C1611F1D7D6C@mail2000.b3.dsh.de
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Ответ на Distinct Values  ("Nicolas" <bnk@medialife.net>)
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Hello Nicolas,

the query you want to construct cannot work because the result of a
query always consists of a consistent table. That means that in a
two-column-table every item on the "left side" has one single opponent
on "the right side". How should your table be built up at all?

I suppose that you want something like the following:

Author     URL
-------    --------
A          http://www.xyz.com          http://www.abc.com
-          - 
B          http://www.def.com          http://www.ijk.com          http://www.rst.com
-          - 

If that is what you want, you cannot manage it. 

Hope this helps ... although it does not really help you :-)

Best regards, Jens Hartwig

-----------------------------------------------------

T-Systems 
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debis Systemhaus GEI GmbH
Address: Eichhornstraße 3, 10785 Berlin
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Internet: http://www.t-systems.de 

> -----Ursprüngliche Nachricht-----
> Von: Nicolas [mailto:bnk@medialife.net]
> Gesendet: Mittwoch, 30. Mai 2001 20:23
> An: pgsql-sql@postgresql.org
> Betreff: [SQL] Distinct Values
> 
> 
> Hi,
> 
> I'm trying to retreive DISTINCT Values from a two colomn table called
> "Books". The colomns are named "Author" and "URL".
> DISTINCT values should be retieved from the "Author" Colomn , 
> and then I
> should be able to retrieve the corresponding URL.
> How do I build the SQL Query ?
> I tried to use: "SELECT DISTINCT Author FROM Books" But this 
> does not allow
> me to fetch the URL value on the other colomn.
> 
> Thanks
> Nicolas
> 
> 
> 
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