Firebase Realtime Database通过按词查询之间进行查询? [英] Firebase Realtime Database Search by word in between the query?
本文介绍了Firebase Realtime Database通过按词查询之间进行查询?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
在我的应用程序中，我在Firebase中有一个实时数据库，其中包含标题，图像，描述和搜索(应用程序中未显示但使用的额外字段包含标题文本，并带有小写字母以进行搜索大小写不敏感).目前，当我以小写或大写或两者混合的方式输入相同的查询时，它会搜索完美，但是当我输入查询之间的某个单词时，它不起作用例如，如果查询为"This is long当我键入"long"时，它什么也没有显示.我被困在帮助他解决这个问题的地方.
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.
我使用了 firebase ui 库:
implementation 'com.firebaseui:firebase-ui-database:4.2.0'
实时数据库屏幕截图:
Realtime Database Screenshot:
这是我的活动代码:
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
editor.apply(); // apply/save the value in our shared preferences
recreate(); //restart activity to take effect
} else if (which == 1) {
{
//sort by oldest
//Edit our shared preferences
SharedPreferences.Editor editor = mSharedPref.edit();
editor.putString("Sort", "oldest"); //where 'Sort' is key & 'oldest' is value
editor.apply(); // apply/save the value in our shared preferences
recreate(); //restart activity to take effect
}
}
}
});
builder.show();
}
}
推荐答案
当我在查询之间键入某些单词时，它不起作用
when I type some word that is in between the query it doesn't work
之所以发生这种情况，是因为Firebase 不不支持本机索引编制或在数据库属性中搜索文本字段.此外，下载整个节点以搜索客户端的字段根本不可行.要启用Firebase实时数据库数据的全文本搜索，建议您使用第三方搜索服务，例如 Algolia 或 Elasticsearch .
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.
此 是有关它如何与Cloud Firestore一起使用的示例，但与您可以将其与Firebase实时数据库一起使用的方式相同.
This is an example on how it works with Cloud Firestore but in the same way you can use it with Firebase realtime database.
这篇关于Firebase Realtime Database通过按词查询之间进行查询?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
