Android SQL Database issue

I am trying to create a simple app as of right now but for some reason either the app is not adding my athlete to the database or is not incrementing the id. I cannot tell. My toString() for my athlete class works good and prints what is in the athlete object but everytime I try to print out my database for an easy read, it prints no values. I believe an issue may be with the addAthlete function in the fragmentB class but am not sure

I am not getting any errors but it is frustrating that it wont add my athlete to the db. Any help would be great! I may just be making a simple mistake but idk.

Main Activity which includes both fragments:

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

    initializeVariables();

    AthleteCreation athleteCreation = new AthleteCreation();
    ListFragment listFragment = new ListFragment();
    android.support.v4.app.FragmentManager manager = getSupportFragmentManager();
    android.support.v4.app.FragmentTransaction transaction = manager.beginTransaction();
    transaction.add(R.id.addAthleteFragment, athleteCreation, "AthleteCreation");
    transaction.add(R.id.listFragment, listFragment, "listFragment");
    transaction.commit();
}

public void initializeVariables(){

}

@Override
public void send(Athlete athlete) {
    android.support.v4.app.FragmentManager manager = getSupportFragmentManager();
    ListFragment listFragment = (ListFragment) manager.findFragmentById(R.id.listFragment);
    listFragment.addAthlete(athlete);
}
}

Add Athlete Fragment(part):

public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    initializeVariables();

    btnAdd.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    switch(v.getId()){
        case R.id.btnAdd:

                athlete.setFirstName(editFirstName.getText().toString());
                athlete.setLastName(editLastName.getText().toString());
                athlete.setAge(Integer.parseInt(editAge.getText().toString()));
                athlete.setGender(genderSelected);
                athlete.setEvent(eventSelected);
                athlete.setTier(Integer.parseInt(editTier.getText().toString()));

                Toast.makeText(getActivity(), athlete.toString(), Toast.LENGTH_LONG).show();
                communicator = (Communicator) getActivity();
                communicator.send(athlete);
    }
}

}

Fragment B which receives info from addAthlete Fragment:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_list, container, false);
    db = new MySQLiteHelper(getActivity(), "AthletesDB", null, 1);
    db.deleteAllAthletes();
    return view;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    // After activity is created in case fragment is created before activity
    initializeVariables();
}
public void initializeVariables(){
    displayTable = (TextView) getView().findViewById(R.id.displayTable);
}

public void addAthlete(Athlete athlete){
    // Add athlete to listview(database)
    firstName = athlete.getFirstName();
    lastName = athlete.getLastName();
    age = athlete.getAge();
    gender = athlete.getGender();
    event = athlete.getEvent();
    tier = athlete.getTier();
    db.addAthlete(athlete);
    displayTable.setText(db.showTable());

}

Database:

public class MySQLiteHelper extends SQLiteOpenHelper{

private static final String DATABASE_NAME = "AthletesDB";
private static final int VERSION = 1;

private static final String TABLE_NAME = "Athletes";
private static final String COLUMN_ID = "ID";
private static final String COLUMN_FIRST_NAME = "First_Name";
private static final String COLUMN_LAST_NAME = "Last_Name";
private static final String COLUMN_AGE = "Age";
private static final String COLUMN_GENDER = "Gender";
private static final String COLUMN_EVENT = "Event";
private static final String COLUMN_TIER = "Tier";

private static final String TABLE_CREATE = "CREATE TABLE " + TABLE_NAME + "( " + COLUMN_ID + " INTEGER AUTOINCREMENT, "
        + COLUMN_FIRST_NAME + " VARCHAR(20), " + COLUMN_LAST_NAME + " VARCHAR(20), " + COLUMN_AGE + " INTEGER, " +
        COLUMN_GENDER + " VARCHAR(20), " + COLUMN_EVENT + " VARCHAR(20), " + COLUMN_TIER + " INTEGER " + ")";

public MySQLiteHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
    super(context, DATABASE_NAME, null, VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(TABLE_CREATE);
}

public void addAthlete(Athlete athlete){
    SQLiteDatabase db = this.getWritableDatabase();

    db.execSQL("INSERT INTO " + TABLE_NAME + "(" + COLUMN_ID + ", " + COLUMN_FIRST_NAME + ", " + COLUMN_LAST_NAME
    + ", " + COLUMN_AGE + ", " + COLUMN_GENDER + ", " + COLUMN_EVENT + ", " + COLUMN_TIER + ")" +
    " VALUES " + "(" + athlete.getID() + ", '" + athlete.getFirstName()
    + "', '" + athlete.getLastName() + "', " + athlete.getAge() + ", '" + athlete.getGender() + "', '" +
    athlete.getEvent() + "', " + athlete.getTier() + ");");
    db.close();
}
public Athlete getAthlete(int id){
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME + " WHERE " + "ID = " + id, null);
    if(cursor != null){
        cursor.moveToFirst();
    }
    Athlete athlete = new Athlete();
    athlete.setID(Integer.parseInt(cursor.getString(0)));
    athlete.setFirstName(cursor.getString(1));
    athlete.setLastName(cursor.getString(2));
    athlete.setAge(Integer.parseInt(cursor.getString(3)));
    athlete.setGender(cursor.getString(4));
    athlete.setEvent(cursor.getString(5));
    athlete.setTier(Integer.parseInt(cursor.getString(6)));

    db.close();
    return athlete;
}
public void deleteAllAthletes(){
    SQLiteDatabase db = this.getWritableDatabase();
    db.execSQL("DELETE FROM " + TABLE_NAME);
    db.close();
}

public String showTable(){
    SQLiteDatabase db = this.getReadableDatabase();
    String athletes = "", template = "";
    Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);

    template = "\tID\t\t First Name\t\t Last Name\t\t Age\t\t Gender\t\t Event\t\t Tier\n";
    if(cursor.moveToFirst()) {
        while (cursor.moveToNext()) {

            Athlete athlete = new Athlete();
            athlete.setID(Integer.parseInt(cursor.getString(0)));
            athlete.setFirstName(cursor.getString(1));
            athlete.setLastName(cursor.getString(2));
            athlete.setAge(Integer.parseInt(cursor.getString(3)));
            athlete.setGender(cursor.getString(4));
            athlete.setEvent(cursor.getString(5));
            athlete.setTier(Integer.parseInt(cursor.getString(6)));

            athletes += athlete.getID() + "\t" + athlete.getFirstName() + "\t" + athlete.getLastName()+ "\t" + athlete.getAge()
                    + "\t" + athlete.getGender() + "\t" + athlete.getEvent() + "\t" + athlete.getTier();
            cursor.moveToNext();
        }
    }
    athletes = template + athletes;
    cursor.close();
    db.close();
    return athletes;
}

}

Interface so the add Athlete fragment can send data to the 2nd fragment:

public interface Communicator {
public void send(Athlete athlete);
}

Thanks for the help