i got double value in database

Hello,

when i insert the value from my form and check the database i found double value Why?

My code Behind:

 SqlCommand query = cnn.CreateCommand();

            query.CommandText = "INSERT INTO [Hotel] ([Type],[Rates],[Name],[City],[Street],[ZipCode],[Country],[BulidingNumber],[ContactFullName],[PhoneNumber],[FaxNumber],[Website],[Email],[Hotel_description],[Check_in],[Check_out],[Distance_center],[Distance_train],[Distance_beach],[FacilitiesDescription],[ServiceDescription],[Terms_condition],[Policy]) VALUES ('" + AddType + "','" + AddRates + "','" + AddHotelName + "','" + AddCity + "','" + AddStreet + "','" + AddZipCode + "','" + AddCountry + "','" + AddBuildingNo + "','" + AddContactName + "','" + AddPhone + "','" + AddFax + "','" + AddWebsite + "','" + AddEmail + "','" + AddHotelDescription + "','" + AddCheckIn + "','" + AddCheckOut + "','" + AddDistanceCenter + "','" + AddDistanceTrain + "','" + AddDistanceBeach + "','" + AddFacilities + "','" + AddService + "','" + AddTerms + "','" + AddPolicy + "'); SELECT SCOPE_IDENTITY();";

            decimal hotelid = (decimal)query.ExecuteScalar();


            query.CommandText = "INSERT INTO [Room_type] ([Hotels_id],[Name]) VALUES ('" + hotelid.ToString() + "','" + AddRoomName + "');";

            query.CommandText += "INSERT INTO [Room_type] ([Hotels_id],[Name]) VALUES ('" + hotelid.ToString() + "','" + AddRoomName2 + "')";

            query.ExecuteNonQuery();
             
             SqlDataReader reader = query.ExecuteReader();



            reader.Close();