linq多表查询?

Question

如下:var categories =
    from p in db.Products
    group p by new
    {
        p.CategoryID,
        p.SupplierID
    }
        into g
        select new
            {
                g.Key,
                g
            };再加上一个表 buyer,变成这样:var categories =
    from p in Products
    join t0 in buyer on p.bid equals t0.bid into et0
    from dt0 in et0.DefaultIfEmpty()
    group p by new
    {
        p.CategoryID,
        p.SupplierID,
        t0.buyer
    } into g
        select new
            {
                g.Key,
                g
            };我想要在select new{},再查出buyer中的buyer名称的,,select new{}里头该怎么写?