select spt.SpecTableId, spt.SpecTableName, count(*), COUNT(distinct dt.BookId) from MainTable as tt
inner join ResTable as rt on tt.ResTableId = rt.ResTableId
inner join DTable as dt on rt.DTableId = dt.DTableId
inner join SpecTable as spt on dp.SpecTableId = spt.SpecTableId
where tt.Flags & 4 > 0 and tt.Count & 1 = 0
group by spt.SpecTableId, spt.SpecTableName

   var result = session.QueryOver(() => MainTable)
                    .JoinAlias(x => MainTable.ResTable, () => ResTable)
                    .JoinAlias(x => ResTable.DTable, () => DTable)
                    .JoinAlias(x => DTable.SpecTable, () => SpecTable)
                    .Where(x => ResTable.SecId == @id (параметр))
                    .And(x => MainTable.Date >= @dateBegin(параметр) && MainTable.Date <= @dateEnd(параметр)) 
                    .And(x => MainTable.Flags == 4)
                    .And(x => MainTable.Count == 0);