在android studio中引用Firestore

我有一些问题,引用一个特定的集合是嵌套的(我认为这个术语),我已经附上了我的数据库结构的图像如下。

enter image description here

编辑:食品系列的图片enter image description here

我基本上有多个文档,里面有一个同名的集合。有没有一种方法可以让我根据用户在前一页点击的餐厅ID动态选择 “食品 “集合,即如果用户选择了ID为01的餐厅,就应该从ID为01的文档中加载 “食品”,等等。

以下是我的代码,用于加载食品的片段。


import android.content.Context;
import android.net.Uri;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.hostapp.Adapters.FoodAdapter;
import com.example.hostapp.Models.FoodModel;
import com.example.hostapp.R;
import com.firebase.ui.firestore.FirestoreRecyclerOptions;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.Query;


public class MainsFragment extends Fragment {

    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference menuref = db.collection("Foods");


    private FoodAdapter adapter;

    String restaurantid = "";


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


        Query query = menuref.whereEqualTo("menuid", restaurantid).orderBy("name");

        FirestoreRecyclerOptions<FoodModel> options = new FirestoreRecyclerOptions.Builder<FoodModel>().
                setQuery(query, FoodModel.class)
                .build();

        adapter = new FoodAdapter(options);

        RecyclerView recyclerView = view.findViewById(R.id.recycler_mains);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this.getActivity()));
        recyclerView.setAdapter(adapter);


        return view;
    }

    private void setUpRecyclerView() {


    }

    @Override
    public void onStart() {
        super.onStart();
        adapter.startListening();
    }

    @Override
    public void onStop() {
        super.onStop();
        adapter.stopListening();
    }
}

对于前一个页面的点击,


import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.RelativeLayout;

import com.example.hostapp.Adapters.RestaurantAdapter;
import com.example.hostapp.Adapters.categoryCardAdapter;
import com.example.hostapp.Models.Restaurant;
import com.example.hostapp.Models.categoryCard;
import com.firebase.ui.firestore.FirestoreRecyclerOptions;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.DocumentSnapshot;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.Query;

public class RestaurantList extends AppCompatActivity {

    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference restaurantref = db.collection("restaurants");
    private RestaurantAdapter adapter;

    String categoryid="";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_restaurant_list);

        setUpRecyclerView();
    }

    private void setUpRecyclerView(){


        //Get intent
        if(getIntent() != null)
            categoryid = getIntent().getStringExtra("categoryid");
        if(!categoryid.isEmpty() && categoryid != null)
        {
            Query query = restaurantref.whereEqualTo("categoryid", categoryid).orderBy("name");

            final FirestoreRecyclerOptions<Restaurant> options = new FirestoreRecyclerOptions.Builder<Restaurant>().setQuery(query, Restaurant.class).build();

            adapter = new RestaurantAdapter(options);

            RecyclerView recyclerView = (RecyclerView) findViewById(R.id.restaurant_recycler);
            recyclerView.setHasFixedSize(true);
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
            recyclerView.setAdapter(adapter);

            adapter.setOnItemClickListerner(new RestaurantAdapter.OnItemClickListener() {
                @Override
                public void onItemClick(DocumentSnapshot documentSnapshot, int position) {
                    Restaurant restaurant = documentSnapshot.toObject(Restaurant.class);
                    Intent foodlist = new Intent(RestaurantList.this, Foodlist.class);
                    foodlist.putExtra("restaurantid", documentSnapshot.getId());
                    startActivity(foodlist);

                }
            });
        }
    }



    @Override
    protected void onStart() {
        super.onStart();
        adapter.startListening();
    }

    @Override
    protected void onStop() {
        super.onStop();
        adapter.stopListening();
    }
}

解决方案:

根据你的意见,要得到所有 Food 所有子库中存在的文件,根据 “文件管理 “的要求,将其归入 “文件管理 “的范畴。menuid 财产,a 火库收藏组查询 是需要的。这个查询是这样的。

Query menuIdQuery = db.collectionGroup("Foods").whereEqualTo("menuid", yourMenuId);

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解决方案

npm运行start没有任何作用,打开了空的命令提示符。

2022-4-20 3:00:09

解决方案

ejabberd - 通过API获取mod_mam的历史消息。

2022-4-20 3:00:11

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