public void AddVehicleDB(string registration, string name, string color, string typeOfVehicle, string brandOfVehcile, Guid?driverID) { using SqlConnection openConnection = new SqlConnection(connectionString); using SqlCommand command = new SqlCommand("AddVehicle", openConnection); command.CommandType = CommandType.StoredProcedure; Guid typeOfVehicleID = VehicleTypes.Find(x => x.Code == typeOfVehicle).ID; Guid brandOfVehicleID = VehicleBrands.Find(x => x.Code == brandOfVehcile).ID; command.Parameters.Add("@Registration", SqlDbType.NVarChar, 10).Value = registration; command.Parameters.Add("@Name", SqlDbType.NVarChar, 30).Value = name; command.Parameters.Add("@Color", SqlDbType.NVarChar, 30).Value = color; command.Parameters.Add("@TypeOfVehicleID", SqlDbType.UniqueIdentifier, 30).Value = typeOfVehicleID; command.Parameters.Add("@BrandOfVehicleID", SqlDbType.UniqueIdentifier, 30).Value = brandOfVehicleID; command.Parameters.Add("@DriverID", SqlDbType.UniqueIdentifier, 30).Value = driverID; openConnection.Open(); int rowsAffected = command.ExecuteNonQuery(); if (rowsAffected > 0) { logger.Debug("The vehicle is inserted in database."); } else { logger.Debug("Insert of vehicle did not succeed."); throw new Exception(); } }