=================================================================================

>>>>>>>>>>>> Main Activity <<<<<<<<<<<<<<<

=================================================================================
public class mainActivity extends AppCompatActivity {

    Button subjects;
    ListView lst;
    sqlite db = new sqlite(this);

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

        subjects = findViewById(R.id.subjects);

        lst = findViewById(R.id.lst);

        subjects.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openDialog();
                showData();
            }
        });
        }

    public void openDialog(){

        showDialog dialog = new showDialog();
        dialog.show(getSupportFragmentManager(),"dialog");
    }

    public void showData(){
        ArrayList arrayList = db.showTableName();
        ArrayAdapter arrayAdapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,arrayList);
        lst.setAdapter(arrayAdapter);
    }
}

=================================================================================

>>>>>>>>>>>> sqlite  <<<<<<<<<<<<<<<

=================================================================================
public class sqlite extends SQLiteOpenHelper{

    private static final String dbName = "data.db";

    public sqlite(Context context) {
        super(context, dbName, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE IF NOT EXISTS tableName (ID INTEGER PRIMARY KEY AUTOINCREMENT, " +
                "NAME TEXT)");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        onCreate(db);
    }


    public Boolean addTableName(String mytableName) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues content = new ContentValues();

        content.put("NAME",mytableName);

        long resualt = db.insert("tableName",null,content);
        return resualt != -1;
    }

    public ArrayList showTableName(){
        ArrayList array = new ArrayList();
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor res = db.rawQuery("SELECT NAME FROM tableName",null);
        res.moveToFirst();
        while (!res.isAfterLast()){
           String name = res.getString(res.getColumnIndex("NAME"));
           array.add(name);
           res.moveToNext();
        }
        return array;
    }
}
=================================================================================

>>>>>>>>>>>> AlertDialog  <<<<<<<<<<<<<<<

=================================================================================
public class showDialog extends AppCompatDialogFragment {
    private EditText createTable;
    Button yes,no;
    sqlite db = new sqlite(getActivity());


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder alert = new AlertDialog.Builder(getActivity(),R.style.CustomDialog);
        LayoutInflater inflater = getActivity().getLayoutInflater();
        View view = inflater.inflate(R.layout.dialog,null);
        alert.setView(view);

        yes = view.findViewById(R.id.btn_yes);
        no = view.findViewById(R.id.btn_no);

        createTable = view.findViewById(R.id.createTable);

        yes.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String tableName = createTable.getText().toString();
                if (!tableName.isEmpty()){
                    db.addTableName(tableName);
                    dismiss();
                } else {
                    Toast.makeText(getContext(), "Please add a valid Name", Toast.LENGTH_SHORT).show();
                }
            }
        });
        no.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dismiss();
            }
        });
        return alert.create();
    }
}
=================================================================================