Postgres error

[Anon]

using float8() functions in order to process a union query with postgress, I constantly get

"Warning: PostgreSQL query failed: ERROR: getTypeOutAndElem: Cache lookup of type 0 failed"

as error message. anybody knows what this means? When I use it with simple examples, it works. Just knowing what the error msg means could help me track down the problem...

[Anon]

maybe this will help you too, dunno:

the 2 queries work perfectly alone, only when using the union, it get the error message...

$overall = "select d.deelnemer_id, d.voornaam, d.familienaam, float8(d.cash) as totaal_waarde
from deelnemers d
where d.deelnemer_id not in (select distinct deelnemer_id from portefeuille)

        UNION
        select d.deelnemer_id, d.voornaam, d.familienaam, (float8( float8(d.cash)+ sum( float8(p.aantal) * float8(a.waarde)))) as totaal_waarde
        from deelnemers d, portefeuille p, aandelen a
        where d.deelnemer_id = p.deelnemer_id AND
              p.aandeel = a.code AND
              d.deelnemer_id in (select distinct deelnemer_id from portefeuille)
        group by d.deelnemer_id, d.voornaam, d.familienaam, d.cash