我正在尝试从Firebase实时数据库中读取“特定”数据。我已经看到了一些示例，这些示例从表中获取所有数据，然后遍历该表以查找所需的数据记录。 下面是我如何保存数据的方法

FirebaseDatabase database;
DatabaseReference foodList;
String categoryId="";

FirebaseRecyclerAdapter<Food,FoodViewHolder>adapter;
FirebaseRecyclerAdapter<Food,FoodViewHolder>searchAdapter;
List<String> suggestList=new ArrayList<>();
MaterialSearchBar materialSearchBar;

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


    database=FirebaseDatabase.getInstance();
    foodList=database.getReference("Foods");

    recyclerView=findViewById(R.id.recycler_food);
    recyclerView.setHasFixedSize(true);
    layoutManager=new LinearLayoutManager(this);
    recyclerView.setLayoutManager(layoutManager);


    if(getIntent()!=null)
    {
        categoryId=getIntent().getStringExtra("CategoryId");
    }
    if(!categoryId.isEmpty() )
    {
        loadListFood(categoryId);
    }


    materialSearchBar=findViewById(R.id.searchBar);
    materialSearchBar.setHint("Enter food name");

    loadSuggestion();
    materialSearchBar.setLastSuggestions(suggestList);
    materialSearchBar.setCardViewElevation(10);
    materialSearchBar.addTextchangelistener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s,int start,int count,int after) {

        }

        @Override
        public void onTextChanged(CharSequence s,int before,int count) {

            List<String>suggest=new ArrayList<>();
            for (String search:suggestList)
            {
                if(search.toLowerCase().contains(materialSearchBar.getText().toLowerCase()))
                    suggest.add(search);
            }
            materialSearchBar.setLastSuggestions(suggest);
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
    materialSearchBar.setOnSearchactionListener(new MaterialSearchBar.OnSearchactionListener() {
        @Override
        public void onSearchStateChanged(boolean enabled) {

            if(!enabled)
            {
                recyclerView.setadapter(adapter);
            }

        }

        @Override
        public void onSearchConfirmed(CharSequence text) {
            startSearch(text);

        }

        @Override
        public void onButtonClicked(int buttonCode) {

        }
    });


}

private void startSearch(CharSequence text) {
    searchAdapter = new FirebaseRecyclerAdapter<Food,FoodViewHolder>(
            Food.class,R.layout.food_item,FoodViewHolder.class,foodList.orderByChild("Name").equalTo(text.toString())// compare Food Name//////
    ) {
        @Override
        protected void populateViewHolder(FoodViewHolder viewHolder,Food model,int position) {

            viewHolder.food_name.setText(model.getName());
            Picasso.with(getBaseContext()).load(model.getImage()).into(viewHolder.food_image);
            final Food local=model;
            viewHolder.setItemClicklistner(new ItemClicklistner() {
                @Override
                public void onClick(View view,int position,boolean isLongClick) {
                    Toast.makeText(FoodList.this,""+local.getName(),Toast.LENGTH_SHORT).show();//there is problem local.getName???????????
                    //Start new Acitvity
                    Intent foodDetail=new Intent(FoodList.this,FoodDetail.class);
                    foodDetail.putExtra("FoodId",searchAdapter.getRef(position).getKey());//send Food ID to new Acitivity
                    startactivity(foodDetail);
                }
            });
        }
    };
    recyclerView.setadapter(searchAdapter);
}

private void loadSuggestion() {
    foodList.orderByChild("MenuId").equalTo(categoryId)
            .addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(Datasnapshot datasnapshot) {
                    for(Datasnapshot postsnapshot:datasnapshot.getchildren() )
                    {
                        Food item=postsnapshot.getvalue(Food.class);
                        suggestList.add(item.getName());

                    }

                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });
}

private void loadListFood(String categoryId) {
    adapter=new FirebaseRecyclerAdapter<Food,FoodViewHolder>(Food.class,foodList.orderByChild("menuId").equalTo(categoryId))
    {
        @Override
        protected void populateViewHolder(FoodViewHolder viewHolder,int position) {
         viewHolder.food_name.setText(model.getName());
         Picasso.with(getBaseContext()).load(model.getImage()).into(viewHolder.food_image);
         final Food local=model;
         viewHolder.setItemClicklistner(new ItemClicklistner() {
             @Override
             public void onClick(View view,boolean isLongClick) {
                 Toast.makeText(FoodList.this,Toast.LENGTH_SHORT).show();

                 Intent foodDetail=new Intent(FoodList.this,FoodDetail.class);
                 foodDetail.putExtra("FoodId",adapter.getRef(position).getKey());
                 startactivity(foodDetail);
             }
         });
        }
    };

    recyclerView.setadapter(adapter);
}
}

更新

当我尝试从Firebase获取数据以更新食物清单时，我没有发现要更改的数据库。下面是我要更新的数据库。