Firebase数据库使用深度嵌套的子级执行SQL“类似”查询

时间:2019-09-24 15:01:47

标签: android firebase-realtime-database

我有一个编辑文本。我正在观看每个字母处的文本更改,并为添加的每个字母查询查询Firebase的请求,从而为我添加了该字母的结果。因此,我尝试了以下提供的以下解决方案-

How to do a simple search in string in Firebase database?

,它似乎不起作用。

我的数据库中有以下JSON配置文件:


{
  "002xUGm1uRXDYc8JpEy7AKFWFyy2" : {
    "contest_uid" : "-LRoyQlTw5vo3CIE3tfb",
    "created_at" : 1543726522,
    "device_id" : "354020096008438",
    "email" : "koushickroy321@gmail.com",
    "is_suspended" : false,
    "is_uploading" : false,
    "last_login_at" : 1543726522,
    "last_upload_started_at" : 0,
    "name" : "gold rush eren patym cash patym",
    "photoUrl" : "*"
  },
  "00IumwilishPwTgPUXX6GmveP5w2" : {
    "contest_uid" : "-LRoyQlTw5vo3CIE3tfb",
    "created_at" : 1543214441,
    "device_id" : "865758030661505",
    "email" : "khushyouheart@gmail.com",
    "is_suspended" : false,
    "is_uploading" : false,
    "last_login_at" : 1543214441,
    "last_upload_started_at" : 0,
    "name" : "Khushal Chouhan",
    "photoUrl" : "*"
  },
  "00TRPNqSi1R41F4SUuhHOgHBdkN2" : {
    "contest_uid" : "-LO3Eg7zf1xh9RGDUy0e",
    "created_at" : 1541355818,
    "device_id" : "357149084088198",
    "is_suspended" : false,
    "is_uploading" : false,
    "last_login_at" : 1541355818,
    "last_upload_started_at" : 0,
    "name" : "Gagan Singh Gaur",
    "photoUrl" : "*"
  },


这就是我已经尝试做的-


mExploreSearchEditText.addTextChangedListener(new TextWatcher() {
      @Override
      public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

      }

      @Override
      public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {


      }

      @Override
      public void afterTextChanged(Editable editable) {
          if (editable.length() < 1) {
            mExploreSearchRecommendedProfiles.setVisibility(View.VISIBLE);
            fetchSixRandomProfiles();
          } else {
            mExploreSearchRecommendedProfiles.setVisibility(View.GONE);
            fetchNewListFromEditable(editable);
          }
      }
    });
  }

  private void fetchNewListFromEditable(Editable editable) {
    String text = editable.toString();
    Query query = FirebaseDatabase.getInstance().getReference().child("profiles").orderByChild("").startAt(text).endAt(text +"\uf8ff");
    query.addListenerForSingleValueEvent(new ValueEventListener() {
      @Override
      public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        if (dataSnapshot.exists()) {
          String users = dataSnapshot.getValue(String.class);
          Timber.tag("similar users").d(users); // <-- I have never got to this point 
        } else {
          Toast.makeText(App.getAppContext(), "snapshot does not exist", Toast.LENGTH_SHORT).show();
        }
      }

      @Override
      public void onCancelled(@NonNull DatabaseError databaseError) {
        Timber.tag("similar users error - " + databaseError.getMessage());
      }
    });
  }


我需要的是添加的每个字母,查询整个“配置文件”表,如果配置文件的名称从一开始就包含整个字符序列,那么我需要名称和photoURL。达到此结果的最佳方法是什么?

1 个答案:

答案 0 :(得分:1)

类似这样的事情应该可以解决:

Query query = FirebaseDatabase.getInstance().getReference().child("profiles").orderByChild("name").startAt(text).endAt(text +"\uf8ff");
query.addListenerForSingleValueEvent(new ValueEventListener() {
  @Override
  public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
    if (dataSnapshot.exists()) {
      for (DataSnapshot snapshot: dataSnapshot.getChildren()) {
        String users = snapshot.child("name").getValue(String.class);
        Timber.tag("similar users").d(users);
      }
    } else {
      Toast.makeText(App.getAppContext(), "snapshot does not exist", Toast.LENGTH_SHORT).show();
    }
  }

  @Override
  public void onCancelled(@NonNull DatabaseError databaseError) {
    Timber.tag("similar users error - " + databaseError.getMessage());
  }
})

更改:

  • 使用orderByChild("name")name属性值的配置文件进行排序/过滤。
  • onDataChange中循环遍历子级,因为查询可以有多个结果。
  • 您需要从每个子快照中获取正确的属性值,因此snapshot.child("name").getValue(String.class)

我还没有做的事情:

  • 在搜索结果中显示用户列表。如果需要,请看一下创建自己的适配器并调用notifyDataSetChanged()