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(at)viafractal(dot)com(dot)br