java - Android:值在插入房间数据库之前被转换为 0 或 1

Question

我正在尝试将带有外键的实体存储到我的房间数据库中。假设我将外键值字段设置为 6。我一直跟踪它，直到插入它并且它保持为 6，但由于某种原因它被存储为 0。如果我没有实例在 6 的家长室数据库上，它会按预期崩溃。但即使它确实存在，它也会存储为 0。如果它是奇数，它会存储为 1。以下是一些相关代码:

@Entity(tableName = "order_table",
        indices = {@Index(value = "shift_id")},
        foreignKeys = @ForeignKey(entity = Shift.class,
                        parentColumns = "id",
                        childColumns = "shift_id",
                        onDelete = ForeignKey.CASCADE)})
public class Order {

    @PrimaryKey(autoGenerate = true)
    private int id;

    @ColumnInfo(name = "shift_id")
    private int shiftId;


    public Order(int shiftId) {
        this.shiftId = shiftId;
    }

    public int getId() {
        return id;
    }

    public int getShiftId() {
        return shiftId;
    }

    public void setId(int id) {
        this.id = id;
    }

@Dao
public interface OrderDao {

    @Insert
    void insert(Order order);
}

   @Query("SELECT * FROM order_table WHERE shift_id = :shiftId")
    LiveData<List<Order>> getAllOrdersFromShift(int shiftId);
}

public class OrderRepository {

    private OrderDao orderDao;

    public OrderRepository(Application application) {
        ShiftsDatabase database = ShiftsDatabase.getInstance(application);
        orderDao = database.orderDao();

    }

    public void insert(Order order) {
        new InsertOrderAsyncTask(orderDao).execute(order);

    }
  public LiveData<List<Order>> getAllOrdersFromShift(List<Integer> ids) {
        return orderDao.getAllOrdersFromShift(ids.get(0));
    }

 private static class InsertOrderAsyncTask extends AsyncTask<Order, Void, Void> {
        private OrderDao orderDao;

        public InsertOrderAsyncTask(OrderDao orderDao) {
            this.orderDao = orderDao;
        }

        @Override
        protected Void doInBackground(Order... orders) {
            orderDao.insert(orders[0]);
            return null;
        }
    }
}

public class OrderViewModel extends AndroidViewModel {

    private OrderRepository repository;

    public OrderViewModel(Application application) {
        super(application);
        repository = new OrderRepository(application);
    }

    public void insert(Order order) {
        repository.insert(order);
    }
    public LiveData<List<Order>> getAllOrdersFromShift(int shiftID){
        List<Integer> ids = new ArrayList<>();
        ids.add(shiftID);
        return repository.getAllOrdersFromShift(ids);
    }
}

注意:我知道数组列表似乎没有必要，但我只是删除了简化所需的代码。

public class OrderFragment extends Fragment {

    private OrderViewModel orderViewModel;
    private RecyclerView recyclerView;
    private int shiftId;
    private Button saveButton;

@Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable       Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.order_fragment, container, false);

        recyclerView = view.findViewById(R.id.tipsRecyclerView);
        recyclerView.addItemDecoration(new DividerItemDecoration(this.getActivity(), LinearLayout.VERTICAL));
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

        final OrderAdapter adapter = new OrderAdapter();
        recyclerView.setAdapter(adapter);

        orderViewModel = ViewModelProviders.of(this).get(OrderViewModel.class);

        orderViewModel.getAllOrdersFromShift(shiftId).observe(getViewLifecycleOwner(), new Observer<List<Order>>() {
            @Override
            public void onChanged(List<Order> orders) {
                adapter.submitList(orders);
            }
        });
    saveButton = view.findViewById(R.id.saveButton);

  saveButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Order newOrder = new Order(shiftId);
                orderViewModel.insert(newOrder);
    }
}

如果将getAllOrdersFromShift中的shiftId改为0，则会显示一些记录。一个奇怪的症状是，如果我尝试将订单存储到 shiftId 为 0 的类次，则会收到外键错误。

我确实在这里找到了有类似问题的人:Room database: inserted ID is always 0

他们只是使用 Kotlin，而我还不知道。

Answer 1

这最终成为查询的问题，在这里无法检测到它，因为我认为这并不重要。原来是这样