How to write query for deleting records in android?

I am new in android. I made an app in which two buttons are there one is start_tracking and it will ask for how many hours you want to track. and other button is show_history in which it will show whatever u tracked. But I stuck in one place in which,if I want to track again and after that if I want to see history again it will delete the previous record and show the latest one.

import android.app.IntentService;
import android.content.ContentValues;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.location.Location;
import android.location.LocationManager;
import android.util.Log;

import com.example.ashwani.abcd.db.MyDatabase;
import com.google.android.gms.location.LocationResult;

import java.util.List;

public class LocationIntentService extends IntentService {
    public static final String TAG = LocationIntentService.class.getSimpleName();

    private LocationManager mLocationManager;

    public LocationIntentService() {
        super("LocationIntentService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        if (LocationResult.hasResult(intent)) {
            LocationResult result = LocationResult.extractResult(intent);
            List<Location> locations = result.getLocations();
            for (Location location : locations) {
                Log.i(TAG,"location is"+ location.getLatitude()+ "," +location.getLongitude());
                MyDatabase myDb = new MyDatabase(this);
                SQLiteDatabase db = myDb.getWritableDatabase();
                db.insert(MyDatabase.TABLE_NAME, null,       getContentValues(location));// here I am inserting the records
            }
            }
        }

    private ContentValues getContentValues(Location location) {
        ContentValues contentValues = new ContentValues();
        contentValues.put(MyDatabase.TIME, location.getTime());
        contentValues.put(MyDatabase.LAT, location.getLatitude());
        contentValues.put(MyDatabase.LNG, location.getLongitude());
        return contentValues;
    }

}