Crossed Reference Query

MS Access has a functionality which is a type of query called "Crossed
Reference Query" (At least, that's the lame translation i got to come up
with).

The syntax is something like this:
TRANSFORM Max(Consulta1.nome) AS [O valor]
SELECT Consulta1.usuario_id, Max(Consulta1.nome) AS [Total de nome]
FROM Consulta1
GROUP BY Consulta1.usuario_id
PIVOT Consulta1.textoitem;

The query Consulta1 is:
SELECT sig_permissoes.usuario_id, sig_menudecontrole.textoitem,
sig_niveis.nome
FROM sig_niveis INNER JOIN (sig_menudecontrole INNER JOIN sig_permissoes ON
sig_menudecontrole.menu_id = sig_permissoes.menu_id) ON sig_niveis.nivel_id
= sig_permissoes.nivel_id
ORDER BY sig_permissoes.usuario_id, sig_menudecontrole.painel_id,
sig_menudecontrole.numeroitem;

Well, i want to know whether is possible to do something like this over
PostgreSQL. If it's needed perl scripts or some other type of scripting, for
me that's ok. the thing is that i need to have that.

Is it possible?

Thanks to all.

Eduardo Mylonas da Silva
Automat Eng. de Automação
Desenvolovimento
mailto: emylonas@automat.com.br
www.automat.com.br