@Dao
public interface UserDao {
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    long insertUser(User user);

    @Delete
    void deleteUser(User user);

    @Update
    void updateUser(User user);

    @Query("SELECT * FROM current_user")
    @Nullable
    User getUser();

    @Query("SELECT * FROM current_user")
    LiveData<User> getUserAsLiveData();
}