public List <SanPham_DTO> Search(SanPham_DTO a, int slmin, int slmax, int dongiamin, int dongiamax, int trongluongmin, int trongluongmax) { var pmh = datacontext.SanPham_Search(a.MaSP, a.MaLoaiSP, a.MaKieuSP, slmin, slmax, dongiamin, dongiamax, trongluongmin, trongluongmax); var MyQuery = (from sp in pmh join lo in datacontext.LOAISPs on sp.MaLoaiSP equals lo.MaLoaiSP join k in datacontext.KIEUSPs on sp.MaKieuSP equals k.MaKieuSP join dv in datacontext.DONVITINHs on lo.MaDonViTinh equals dv.MaDonViTinh select new SanPham_DTO { MaLoaiSP = sp.MaLoaiSP.GetValueOrDefault(), TenLoaiSP = lo.TenLoaiSP, MaSP = sp.MaSP, MaKieuSP = sp.MaKieuSP.GetValueOrDefault(), TrongLuong = (float)sp.TrongLuong.GetValueOrDefault(), DonGiaBan = sp.DonGiaBan.GetValueOrDefault(), SoLuongTon = sp.SoLuongTon.GetValueOrDefault(), TenKieuSP = k.TenKieuSP, TenDonViTinh = dv.TenDonViTinh }); return(MyQuery.ToList()); }