How to add multiple edit text and spinner data into SQLite database?

#xml files for layout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:orientation="vertical"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Name"
        android:id="@+id/textViewName" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editTextName" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Address"
        android:id="@+id/textViewAddress" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editTextAddress" />

    <Button
        style="?android:attr/buttonStyleSmall"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Add"
        android:id="@+id/btnAdd" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="View Peoples"
        android:id="@+id/btnView" />
</LinearLayout>
The java file is as follows
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity implements View.OnClickListener {

    private EditText editTextName;
    private EditText editTextAdd;
    private Button btnAdd;
    private Button btnView;

    private SQLiteDatabase db;

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

        createDatabase();

        editTextName = (EditText) findViewById(R.id.editTextName);
        editTextAdd = (EditText) findViewById(R.id.editTextAddress);

        btnAdd = (Button) findViewById(R.id.btnAdd);
        btnView = (Button) findViewById(R.id.btnView);

        btnAdd.setOnClickListener(this);
        btnView.setOnClickListener(this);
    }


    protected void createDatabase(){
        db=openOrCreateDatabase("PersonDB", Context.MODE_PRIVATE, null);
        db.execSQL("CREATE TABLE IF NOT EXISTS persons(id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, name VARCHAR,address VARCHAR);");
    }

    protected void insertIntoDB(){
        String name = editTextName.getText().toString().trim();
        String add = editTextAdd.getText().toString().trim();
        if(name.equals("") || add.equals("")){
            Toast.makeText(getApplicationContext(),"Please fill all fields", Toast.LENGTH_LONG).show();
            return;
        }

        String query = "INSERT INTO persons (name,address) VALUES('"+name+"', '"+add+"');";
        db.execSQL(query);
        Toast.makeText(getApplicationContext(),"Saved Successfully", Toast.LENGTH_LONG).show();
    }


    @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_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        if(v == btnAdd){
            insertIntoDB();
        }
    }
}