RecyclerView ne met pas à jour après la suppression d'un élément de sqlite?

J'ai peuplé recyclerview de sqlite .en cliquant sur chaque ligne ,chaque ligne va supprimer de sqlite mais recyclerview ne montrant pas de mise à jour de la liste après la supprimer. Recycleur afficher la liste mise à jour seulement après le lancement de l'activité une fois de plus. Ma question est comment mettre à jour le recycleur voir bientôt après la suppression d'un élément à partir de la recylcerview sans actualisation.

voici mes code

SecondActivity.java

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.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class SecondActivity extends AppCompatActivity {
DatabaseHelpher helpher;
List<DatabaseModel> dbList;
RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
helpher = new DatabaseHelpher(this);
dbList= new ArrayList<DatabaseModel>();
dbList = helpher.getDataFromDB();
mRecyclerView = (RecyclerView)findViewById(R.id.recycleview);
mRecyclerView.setHasFixedSize(true);
// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
// specify an adapter (see also next example)
mAdapter = new RecyclerAdapter(this,dbList);
mRecyclerView.setAdapter(mAdapter);
mAdapter.notifyDataSetChanged ();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_second, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
}

DatabaseHelpher.java

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class DatabaseHelpher extends SQLiteOpenHelper {
private static final String DATABASE_NAME="student";
private static final int DATABASE_VERSION = 1;
private static final String STUDENT_TABLE = "stureg";
private static final String STU_TABLE = "create table "+STUDENT_TABLE +"(name TEXT,email TEXT primary key,roll TEXT,address TEXT,branch TEXT)";
Context context;
public DatabaseHelpher(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(STU_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + STUDENT_TABLE);
// Create tables again
onCreate(db);
}
/* Insert into database*/
public void insertIntoDB(String name,String email,String roll,String address,String branch){
Log.d("insert", "before insert");
// 1. get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// 2. create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put("name", name);
values.put("email", email);
values.put("roll", roll);
values.put("address", address);
values.put("branch", branch);
// 3. insert
db.insert(STUDENT_TABLE, null, values);
// 4. close
db.close();
Toast.makeText(context, "insert value", Toast.LENGTH_LONG);
Log.i("insert into DB", "After insert");
}
/* Retrive  data from database */
public List<DatabaseModel> getDataFromDB(){
List<DatabaseModel> modelList = new ArrayList<DatabaseModel>();
String query = "select * from "+STUDENT_TABLE;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query,null);
if (cursor.moveToFirst()){
do {
DatabaseModel model = new DatabaseModel();
model.setName(cursor.getString(0));
model.setEmail(cursor.getString(1));
model.setRoll(cursor.getString(2));
model.setAddress(cursor.getString(3));
model.setBranch(cursor.getString(4));
modelList.add(model);
}while (cursor.moveToNext());
}
Log.d("student data", modelList.toString());
return modelList;
}
/*delete a row from database*/
public void deleteARow(String email){
SQLiteDatabase db= this.getWritableDatabase();
db.delete(STUDENT_TABLE, "email" + " = ?", new String[] { email });
db.close();
}
}

DatabaseModel.java

public class DatabaseModel {
private String name;
private String roll;
private String address;
private String branch;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRoll() {
return roll;
}
public void setRoll(String roll) {
this.roll = roll;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getBranch() {
return branch;
}
public void setBranch(String branch) {
this.branch = branch;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}

RecyclerAdapter.java

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
static   List<DatabaseModel> dbList;
static  Context context;
static DatabaseHelper dh;
RecyclerAdapter(Context context, List<DatabaseModel> dbList ){
this.dbList = new ArrayList<DatabaseModel>();
this.context = context;
this.dbList = dbList;
dh=new DatabaseHelper(context);
}
@Override
public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(
R.layout.item_row, null);
// create ViewHolder
ViewHolder viewHolder = new ViewHolder(itemLayoutView);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerAdapter.ViewHolder holder, int position) {
holder.name.setText(dbList.get(position).getName());
holder.email.setText(dbList.get(position).getEmail());
}
@Override
public int getItemCount() {
return dbList.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView name,email;
public ViewHolder(View itemLayoutView) {
super(itemLayoutView);
name = (TextView) itemLayoutView
.findViewById(R.id.rvname);
email = (TextView)itemLayoutView.findViewById(R.id.rvemail);
itemLayoutView.setOnClickListener(this);
}
@Override
public void onClick(View v) {
dh.delete(dbList.get(getAdapterPosition()).getEmail);
Toast.makeText(RecyclerAdapter.context, "you have clicked Row " + getAdapterPosition(), Toast.LENGTH_LONG).show();
}
}
}

j'ai essayé de mettre à jour recyclerview à l'aide de mAdapter.notifyDataSetChanged (); mais il ne fonctionne pas pour moi.veuillez sugget moi.Merci