CODEWITHSUNDEEP
androidfirebasefirebase-realtime-databasefirebaseui
Jama Mohamed
Jama Mohamed

Reputation: 3405

How to write Firebase query to filter out data?

I wanted to write a query so as to filter the data using an edittext, the code below does work but bring all of the unwanted searched data. Can you please help me? The JSON object is as follows: The data I wanted to filter out is the username

firebase json object

public class SearchActivity extends AppCompatActivity {

ListView searchList;
DatabaseReference databaseReference;
FirebaseListAdapter<SearchDetails> listAdapter;
String search;
EditText editTextSearch;

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

    searchList = (ListView) findViewById(R.id.listViewSearch);
    databaseReference = FirebaseDatabase.getInstance().getReference().child("Search Users");

    editTextSearch = (EditText) findViewById(R.id.editTextSearch);


    editTextSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

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

        }

        @Override
        public void afterTextChanged(Editable s) {
            search = editTextSearch.getText().toString();
            if (search.equals("")){
                searchList.setAdapter(null);
            }else{
                searchList.setAdapter(listAdapter);
            }
        }
    });

    Query query = databaseReference.startAt(search).endAt(search+"~").limitToFirst(10);
    listAdapter = new FirebaseListAdapter<SearchDetails>(
            this,
            SearchDetails.class,
            R.layout.search_layout,
            query
    ) {
        @Override
        protected void populateView(View v, SearchDetails model, int position) {
            TextView username = (TextView) v.findViewById(R.id.textViewUsername);
            username.setText(model.getUsername());
            TextView name = (TextView) v.findViewById(R.id.textViewName);
            name.setText(model.getName());
        }
    };

}
}

Upvotes: 1

Views: 997

Answers (2)

droidchef
droidchef

Reputation: 2307

In order to solve this problem we need to understand a few things about Firebase, that a lot of developers might overlook.

  • It is a NoSQL based Data Storage, so you have to structure your data accordingly.
  • Firebase allows you to nest nodes into your data structure for up to 32 levels deep, and this can be easily abused.

The problem that I think you have at hand is to "have an EditText that allows user to search for usernames of your users.

How I would suggest you to tackle this is by flattening the structure of your data like so

enter image description here You can have objects inside usernames array. Each object's key is the username and the value is another object with an empty-key : "" like so.

And you can then have another array of users where again the keys are usernames and rest of the data lives as an object under it.

Now you can easily run your Filter Query on usernames without worrying about the overhead of fetching unnecessary data in that query.

And once you know which username was selected, you can query users to fetch that exact user from the array.

Upvotes: 1

Rihab
Rihab

Reputation: 67

Query query = databaseReference.orderByChild("username").startAt(search).endAt(search+"~").limitToFirst(10);

Upvotes: 0

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