From: Tomasz Myrta <jasiek@klaster.net>
To: Együd Csaba <csegyud@freemail.hu>
Cc: pgsql-sql@postgresql.org
Subject: Re: Getting one row for each subquery row...?
Date: Fri, 20 Jun 2003 08:11:58 +0200
Message-ID: <3EF2A5AE.1030006@klaster.net> (raw)
In-Reply-To: <007901c336ea$9cee0e80$230a0a0a@compaq>
References: <007901c336ea$9cee0e80$230a0a0a@compaq>
Dnia 2003-06-20 07:12, Użytkownik Együd Csaba napisał:
> Hi All,
> here are my three tables. I wold like to list them in the following way: I
> need all the columns from t_stockchanges, and one field for the
> productgroup
> the t_stockchanges.productid belongs to.
>
> But one product can belong to many groups, so i would need one row for each
> group for each product.
>
> My bad query is:
> ------------------------
> DB=# select t_stockchanges.productid, (select name from t_productgroups
> where id=(select productgroupid from t_prod_in_pgr where
> productid=t_stockchanges.productid)) as pgroup from t_stockchanges;
> ERROR: More than one tuple returned by a subselect used as an expression.
> DB=#
> ---------------
> Yes, this is absolutelly true, but I would like postgres to give me all the
> tuples found. How can I ask him to do so?
>
> Thank you,
> -- Csaba
Sorry, if you want all combination of grups and products, you need to rewrite
your query:
select
t_stockchanges.productid,
t_productgroups.name as pgroup
from
t_stockchanges
join t_prod_in using (productid)
join t_productgroups on (id=productgroupid)
or something like this.
Tomasz
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To: pgsql-sql@postgresql.org
Cc: jasiek@klaster.net, csegyud@freemail.hu
Subject: Re: Getting one row for each subquery row...?
In-Reply-To: <3EF2A5AE.1030006@klaster.net>
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