Android Using a Thread to Execute SQLite Queries

I am trying to create a database of restaurants and their items for an app as a starter project to get familiar with android. I have a list from a previous activity where a user clicks on the name of the restaurant and the items are shown. I created a helperDB class to handle the insert statements and database setup, although when I called my insert method from inside a new thread, they do not seem to execute. I have provided the code below:

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

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    Intent intent = getIntent();
    String barName = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
    final TextView tv = (TextView) findViewById(R.id.name);
    tv.setText(barName);

    restaurants = new ArrayList<String>();
    mydb = new DBHelper(this);

   new Thread(new Runnable() {
        @Override
        public void run() {
            mydb.insertDrink("cake", "McD's", 8);
            mydb.insertDrink("muffin", "The Woods", 8);
            restaurants = mydb.getDrinks("The Woods");
            System.out.println(restaurants);
        }
    }).start();


    ArrayAdapter arrayAdapter=new ArrayAdapter(this,android.R.layout.simple_list_item_1, restaurants);

    obj = (ListView)findViewById(R.id.listview);
    obj.setAdapter(arrayAdapter);
}

The code for the insert statement and getDrinks method are as follows:

public boolean insertDrink(String drink, String name, int price){
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();

    contentValues.put("drink", drink);
    contentValues.put("name", name);
    contentValues.put("price", price);
    db.insert("Bars", null, contentValues);
    return true;
}
public ArrayList<String> getDrinks(String name){
    ArrayList<String> arrayList = new ArrayList<>();

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor res = db.rawQuery("select * from Bars", null);
    res.moveToFirst();

    while(res.isAfterLast() == false){
        arrayList.add(res.getString(res.getColumnIndex(BAR_COLUMN_DRINK)));
        res.moveToNext();
    }
    return arrayList;
}

I know that I am not supposed to access any android toolkits from any thread besides the UI thread, although I don't think I am doing that. If this is not the normal way to populate a SQLite android database, I of course am willing to learn where to do that as well.