java - Firebase Realtime Database Search by word in between the query?

Question

In my application, I have a real-time database in Firebase containing Title, Image, Description, Search(an extra field that is not displayed in the app but used contains the text of title with small case letters to make search case insensitive). Currently when I type query same to same either in small case or capital or with mixture of both it searches perfect, but when I type some word that is in between the query it doesn't work For example if the query is "This is long title" when I type "long" it shows nothing. I'm stuck help he solve this.

I have used firebase ui library:

implementation 'com.firebaseui:firebase-ui-database:4.2.0'

Realtime Database Screenshot:

Here is my activity code:

package com.blogspot.atifsoftwares.firebaseproject;

import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;

import java.io.ByteArrayOutputStream;

public class PostsListActivity extends AppCompatActivity {

    LinearLayoutManager mLayoutManager; //for sorting
    SharedPreferences mSharedPref; //for saving sort settings
    RecyclerView mRecyclerView;
    FirebaseDatabase mFirebaseDatabase;
    DatabaseReference mRef;

    FirebaseRecyclerAdapter<Model, ViewHolder> firebaseRecyclerAdapter;
    FirebaseRecyclerOptions<Model> options;

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

        //Actionbar
        ActionBar actionBar = getSupportActionBar();
        //set title
        mSharedPref = getSharedPreferences("SortSettings", MODE_PRIVATE);
        String mSorting = mSharedPref.getString("Sort", "newest"); //where if no settingsis selected newest will be default

        if (mSorting.equals("newest")) {
            mLayoutManager = new LinearLayoutManager(this);
            //this will load the items from bottom means newest first
            mLayoutManager.setReverseLayout(true);
            mLayoutManager.setStackFromEnd(true);
        } else if (mSorting.equals("oldest")) {
            mLayoutManager = new LinearLayoutManager(this);
            //this will load the items from bottom means oldest first
            mLayoutManager.setReverseLayout(false);
            mLayoutManager.setStackFromEnd(false);
        }

        //RecyclerView
        mRecyclerView = findViewById(R.id.recyclerView);
        mRecyclerView.setHasFixedSize(true);

        //send Query to FirebaseDatabase
        mFirebaseDatabase = FirebaseDatabase.getInstance();
        mRef = mFirebaseDatabase.getReference("Data");

        showData();
    }

    //show data
    private void showData(){
        options = new FirebaseRecyclerOptions.Builder<Model>().setQuery(mRef, Model.class).build();

        firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Model, ViewHolder>(options) {
            @Override
            protected void onBindViewHolder(@NonNull ViewHolder holder, int position, @NonNull Model model) {
                holder.setDetails(getApplicationContext(), model.getTitle(), model.getDescription(), model.getImage());
            }

            @NonNull
            @Override
            public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                //Inflating layout row.xml
                View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.row, parent, false);

                ViewHolder viewHolder = new ViewHolder(itemView);
                //item click listener
                viewHolder.setOnClickListener(new ViewHolder.ClickListener() {
                    @Override
                    public void onItemClick(View view, int position) {
                        //get data from firebase at the position clicked
                        String mTitle = getItem(position).getTitle();
                        String mDesc = getItem(position).getDescription();
                        String mImage = getItem(position).getImage();

                        //pass this data to new activity
                        Intent intent = new Intent(view.getContext(), PostDetailActivity.class);
                        intent.putExtra("title", mTitle); // put title
                        intent.putExtra("description", mDesc); //put description
                        intent.putExtra("image", mImage); //put image url
                        startActivity(intent); //start activity
                    }

                    @Override
                    public void onItemLongClick(View view, int position) {
                        //Todo implement you on long click functionality here
                    }
                });

                return viewHolder;
            }
        };

        //set layout as LinearLayout
        mRecyclerView.setLayoutManager(mLayoutManager);
        firebaseRecyclerAdapter.startListening();
        //set adapter to firebase recycler view
        mRecyclerView.setAdapter(firebaseRecyclerAdapter);
    }

    //search data
    private void firebaseSearch(String searchText) {

        //convert string entered in SearchView to lowercase
        String query = searchText.toLowerCase();

        Query firebaseSearchQuery = mRef.orderByChild("search").startAt(query).endAt(query + "uf8ff");


        options = new FirebaseRecyclerOptions.Builder<Model>().setQuery(firebaseSearchQuery, Model.class).build();

        firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Model, ViewHolder>(options) {
            @Override
            protected void onBindViewHolder(@NonNull ViewHolder holder, int position, @NonNull Model model) {
                holder.setDetails(getApplicationContext(), model.getTitle(), model.getDescription(), model.getImage());
            }

            @NonNull
            @Override
            public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                //Inflating layout row.xml
                View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.row, parent, false);

                ViewHolder viewHolder = new ViewHolder(itemView);
                //item click listener
                viewHolder.setOnClickListener(new ViewHolder.ClickListener() {
                    @Override
                    public void onItemClick(View view, int position) {
                        //get data from firebase at the position clicked
                        String mTitle = getItem(position).getTitle();
                        String mDesc = getItem(position).getDescription();
                        String mImage = getItem(position).getImage();

                        //pass this data to new activity
                        Intent intent = new Intent(view.getContext(), PostDetailActivity.class);
                        intent.putExtra("title", mTitle); // put title
                        intent.putExtra("description", mDesc); //put description
                        intent.putExtra("image", mImage); //put image url
                        startActivity(intent); //start activity
                    }

                    @Override
                    public void onItemLongClick(View view, int position) {
                        //Todo implement you on long click functionality here
                    }
                });

                return viewHolder;
            }
        };

        //set layout as LinearLayout
        mRecyclerView.setLayoutManager(mLayoutManager);
        firebaseRecyclerAdapter.startListening();
        //set adapter to firebase recycler view
        mRecyclerView.setAdapter(firebaseRecyclerAdapter);

    }


    //load data into recycler view onStart
    @Override
    protected void onStart() {
        super.onStart();
        if (firebaseRecyclerAdapter !=null){
            firebaseRecyclerAdapter.startListening();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //inflate the menu; this adds items to the action bar if it present
        getMenuInflater().inflate(R.menu.menu, menu);
        MenuItem item = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                firebaseSearch(query);
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                //Filter as you type
                firebaseSearch(newText);
                return false;
            }
        });
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        //handle other action bar item clicks here
        if (id == R.id.action_sort) {
            //display alert dialog to choose sorting
            showSortDialog();
            return true;
        }
        if (id == R.id.action_add) {
            //start Add Post Activity
            startActivity(new Intent(PostsListActivity.this, AddPostActivity.class));
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void showSortDialog() {
        //options to display in dialog
        String[] sortOptions = {" Newest", " Oldest"};
        //create alert dialog
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Sort by") //set title
                .setIcon(R.drawable.ic_action_sort) //set icon
                .setItems(sortOptions, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // The 'which' argument contains the index position of the selected item
                        // 0 means "Newest" and 1 means "oldest"
                        if (which == 0) {
                            //sort by newest
                            //Edit our shared preferences
                            SharedPreferences.Editor editor = mSharedPref.edit();
                            editor.putString("Sort", "newest"); //where 'Sort' is key & 'newest' is value
                           

Answer 1

when I type some word that is in between the query it doesn't work

This is happening because Firebase does not support native indexing or search for text fields in database properties. Additionally, downloading an entire node to search for fields client-side isn't practical at all. To enable full text search of your Firebase realtime database data, I recommend you to use a third-party search service like Algolia or Elasticsearch.

This is an example on how it works with Cloud Firestore but in the same way you can use it with Firebase realtime database.