Does it have to be in one row?
Otherwise, assuming that person_data.d_person_id references person.a_id and
person_data.d_attribute_id references person_attribute.a_id:
select a.a_name from person p, person_data d, person_attribute a where
p.p_name = 'UserYou'reLookingFor' AND p.p_id = d.d_person_id AND
d.d_attribute_id = a.a_id
Would return a list of attributes the person has, one per row.
----- Original Message -----
From: <rdg@viafractal.com.br>
To: <pgsql-sql@postgresql.org>
Cc: <rdg@viafractal.com.br>
Sent: Thursday, August 24, 2000 11:24 AM
Subject: [SQL] weird structure
> Hi,
>
> Consider the following tables/fields:
> table "person": fields "p_id", "p_name".
> table "person_attribute": fields "a_id", "a_name".
> table "person_data": fields "d_person_id", "d_attribute_id",
> "d_value".
>
> Also consider that a person may not have data related to all possible
> attributes.
>
> Using this structure, how could I retrieve in one row with a single
> select statement all attributes from a person (showing null to
> attributes that were not registered to him)?
>
> Thanks for any suggestion,
> --
> Renato
> Sao Paulo - SP - Brasil
> rdg@viafractal.com.br
>