Set SPINNER empty before populate values from SQLite

I'm new in Android Programming..

I would like to ask that How can I set the spinner into empty before populate the values from SQLite database?

Below are my codes which the spinner only fetch my values from database.

Example:

Spinner

• English

• Mathematics

Before choosing one of the spinner value, I want to show the spinner is empty first~

Timetable.java

public void getAllResultsA(){
        List<String> resultsA = databaseHelper.getAllResultsA();
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, resultsA){

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {

                View v = super.getView(position, convertView, parent);
                if (position == getCount()) {
                    ((TextView)v.findViewById(android.R.id.text1)).setText("");
                    ((TextView)v.findViewById(android.R.id.text1)).setHint(getItem(getCount())); //"Hint to be displayed"
                }

                return v;
            }

            @Override
            public int getCount() {
                return super.getCount()-1;            // you don't display last item. It is used as hint.
            }

        };
        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        // attaching data adapter to spinner
        tvMon1.setAdapter(dataAdapter);
        tvMon1.setSelection(dataAdapter.getCount());
        tvTues1.setAdapter(dataAdapter);
        tvWeb1.setAdapter(dataAdapter);
        tvThurs1.setAdapter(dataAdapter);
        tvFri1.setAdapter(dataAdapter);
    }