How to retrieve data from database and display it on TextView in android eclipse

i'm making simple application that store and retrieve data in database, i can store a data but i'am having a problem in retrieving on it, i want to retrieve the data and display it on TextView:

Here is my MySQLiteHelper.java

public class MySQLiteHelper extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "test";
    private static final String DATABASE_TABLE = "test_table";
    private static final String CREATE_TABLE = "CREATE TABLE " + DATABASE_TABLE + " (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER)";

    public MySQLiteHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {   
        db.execSQL(CREATE_TABLE);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
        this.onCreate(db);
    }

    //Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_AGE = "age";

    //This will store data and this is OK
    public void addNameAndAge(ReturningClass sample) {
            SQLiteDatabase db = this.getWritableDatabase();
            ContentValues values = new ContentValues();
            values.put(KEY_NAME, sample.getName());                                                             
            values.put(KEY_AGE, sample.getAge()); 
            db.insert(DATABASE_TABLE, null, values);
            db.close();
    }

    //This will retrieve data, and this is my problem
    public String[] getNameAndAge(){
        //I want to check first here if table has a value
        //if the table is empty then return 'No Data Yet' value
        //else then retrieve the data, but i don't know how to do that
        String selectQuery = "SELECT  * FROM " + DATABASE_TABLE;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
                 String[] data = null;
        if (cursor.moveToFirst()) {
            do {
               // I don't know how i going to retrieve data here
            } while (cursor.moveToNext());
        }
        db.close();
        return data;
    }

}

}

Here is my ReturningClass.java model:

public class ReturningClass {

    private int id;
    private String nameThis;
    private String ageThis;

    public ReturningClass(){}

    public ReturningClass(String name, String age) {
        super();
        this.nameThis = name;
        this.ageThis = age;
    }

    public String getName() {
        return nameThis;
    }
    public String getAge() {
        return ageThis;
    }
    public int getId() {
        return id;
    }
}

and here is my MainActivity.java :

public class MainActivity extends Activity implements View.OnClickListener {

    public void onCreate(Bundle saveInstanceState) {
        super.onCreate(saveInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.main_activity);

        db = new MySQLiteHelper(this);//DATABASE

        TextView nameTextView = (TextView) findViewById(R.id.nameId);
        TextView ageTextView = (TextView) findViewById(R.id.ageId);

        String[] dataGet = db.getNameAndAge();  
        if(dataGet == "No Data Yet"){
           //Some code here...
        }else{
           nameTextView.setText(dataGet[1]);
           ageTextView.setText(dataGet[2]);
        }

} }

I am very new in android developing so any helped will be appreciated. Thank you!