Re: [SQL] SELECT DISTINCT

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От Peter Garner
Тема Re: [SQL] SELECT DISTINCT
Дата
Msg-id 19990102024050.4325.rocketmail@send206.yahoomail.com
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Список pgsql-sql
Hi Tim,

> select distinct fld_city, fld_zip from tbl_zip_city where
fld_state='IA' and
> fld_country='us';
>
> That query does not return distinct cities any more. It returns all
cities
> (because each city can have several zip codes).
>

Yes, that is what it is supposed to do, heheheh.  Try something like :

select city, min (zip_code)
from tbl_zip_city
group by city
having fld_state = 'IA'

Basically since you have multiple zip codes and want only one per city
you have to tell the sql engine which zip code to pick.  It won't just
select one at random.  I hope this helps! :-)
==

Peace,

Peter

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