Question

我在firestore中的集合中有Array对象。当我调用集合（Orders）来获得单个订单时，它会正确地检索所有对于名为“食品”的对象Array的期望。

参考订单

    mOrderRef = mFirestore.collection("orders").document(orderId);

onEvent功能

   @Override
   public void onEvent(DocumentSnapshot documentSnapshot, 
   FirebaseFirestoreException e) {
     if (e != null) {
         Log.w(TAG, "order:onEvent", e);
         return;
     }


     onOrderLoaded(documentSnapshot.toObject(Order.class));
  }

onOrderLoaded函数

    private void onOrderLoaded(Order order) {


    Log.d(TAG, String.valueOf(order.getMenu())); // why is printing null?

   }

这是订单类的完整代码

      @IgnoreExtraProperties
   public class Order {

public static final String FIELD_USER_NAME = "username";
public static final String FIELD_USER_PHONE = "user_phone_number";
public static final String FIELD_USER_ID = "user_id";
public static final String FIELD_RESTAURANT_NAME = "restaurant_name";
public static final String FIELD_RESTAURANT_ID = "restaurant_id";
public static final String FIELD_STATUS = "status";
public static final String FIELD_SUBMITTED_AT = "submitted_at";
public static final String FIELD_TOTAL_COST = "total_cost";
public static final String FIELD_MENU = "foods";

private String username;
private String user_phone_number;
private String user_id;
private String restaurant_id;
private String restaurant_name;
private String status;
private Date submitted_at;
private Integer total_cost;
private Menu[] foods;

public Order() {}

public Order(String user_name, String user_phone_number, String user_id, String restaurant_id, String restaurant_name, String status, Date submitted_at, Integer total_cost, Menu[] foods) {
    this.username = user_name;
    this.user_phone_number = user_phone_number;
    this.user_id = user_id;
    this.restaurant_id = restaurant_id;
    this.restaurant_name = restaurant_name;
    this.status = status;
    this.submitted_at = submitted_at;
    this.total_cost = total_cost;
    this.foods = foods;
}

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getUser_phone_number() {
    return user_phone_number;
}

public void setUser_phone_number(String user_phone_number) {
    this.user_phone_number = user_phone_number;
}

public String getUser_id() {
    return user_id;
}

public void setUser_id(String user_id) {
    this.user_id = user_id;
}

public String getRestaurant_id() {
    return restaurant_id;
}

public void setRestaurant_id(String restaurant_id) {
    this.restaurant_id = restaurant_id;
}

public String getRestaurant_name() {
    return restaurant_name;
}

public void setRestaurant_name(String restaurant_name) {
    this.restaurant_name = restaurant_name;
}

public String getStatus() {
    return status;
}

public void setStatus(String status) {
    this.status = status;
}

public Date getSubmitted_at() {
    return submitted_at;
}

public void setSubmitted_at(Date submitted_at) {
    this.submitted_at = submitted_at;
}

public Integer getTotal_cost() {
    return total_cost;
}

public void setTotal_cost(Integer total_cost) {
    this.total_cost = total_cost;
}

public Menu[] getMenu() {
    return foods;
}

public void setMenu(Menu[] foods) {
    this.foods = foods;
}
   }

菜单型号

public class Menu {

    public static final String FIELD_ID = "id";
    public static final String FIELD_NAME = "name";
    public static final String FIELD_QUANTITY = "quantity";
    public static final String FIELD_PRICE = "price";

    private String id;
    private String name;
    private String quantity;
    private String price;


    public Menu() {}

    public Menu(String id, String name, String quantity, String price) {
        this.id = id;
        this.name = name;
        this.quantity = quantity;
        this.price = price;
    }

    // Getter and Setter

}

我在firestore上的Order集合中有字段Array对象，问题是如何映射Menu模型列表？

公司的FireStore：

Answer 1

没有您的数据库规则或文档创建代码，很难说，但您的Menu模型似乎存储为Order模型的子集合。 FireStore only performs "shallow" queries因此您需要执行其他查询以获取特定订单文档的Menu子集的所有文档。

在Colletion Fistore Android中的对象数组

1 个答案: