how should I open and close my database properly

Question

I have an app which stores some data in a SQLite DB.Also I\'m doing a lot of query an requery in my app.I have about 15 activities in it.And almoust all use the DB to query for

Answer 1

When you retrieve your dbAdapter from you MyApplication class, do it in a lazy fashion, creating it only when needed. In my implementation, I also open it at this time.

public static DbAdapter getDbAdapter() {
    if (dbAdapter == null) {
        dbAdapter = new DbAdapter();
    }
    dbAdapter.open();
    return dbAdapter;
}

It is a good idea to use getReadableDatabase() or getWriteableDatabase() in the open method of your database adapter.

Also, I think it works better to retrieve your adapter in onStart() and close it in onStop() of the activities where it is being used, rather than using onCreate() and onDestroy().

@Override
protected void onStop() {
    super.onStop();
    MyApp.closeDatabase();
}

And in the MyApp class...

public static void closeDatabase() {
    dbAdapter.close();
}