using multiple Schema with NHibernate

Question

hello every one i using NHibernate with PostgreSQL, My database has many Schema, so i must retrieve data from multiple schema:

I have a Sql Query like this: in this case i have two Schema: medibv0409 and medibv

select a.mabn,1 as loaiba,e.nhantu,b.maql,to_number(to_char(a.ngay,'yyyy'))-to_number(c.namsinh) as tuoi,c.phai,b.sonao, b.mubaohiem,b.cotsongco,b.mocapcuu,b.bivo,b.gaiquai,b.loaimu,b.ruoubia,b.mau,b.ptgaytn, b.nhapvien,b.tuvong,b.xinve,b.mabv from ((medibv0409.tainantt a inner join medibv0409.tainangt b on a.maql=b.maql) inner join medibv.benhandt e on a.maql=e.maql) inner join medibv.btdbn c on a.mabn=c.mabn

How can i change it to HQL In NHibernate

Every one Help me, Thanks.