Hello, i'm creating a query but everytime i use the last condition it doesn't bring any results, this is my query:

select * from hardware h, usuarios_cia u, oficina o, modelos m, marcas ma, hard_local hl; 
where h.usuario=u.codigo and u.oficina=o.codigo and h.modelo=m.codigo and m.marca=ma.codigo;
and h.host=hl.host

And i know that accomplish this query, even i build a query in order to probe this:

select * from hardware, hard_local, tipo_local where hardware.host=hard_local.host and hard_local.tipo=tipo_local.tipo

what is wrong in the first query?
Thanks.