prepbgg prepbgg - 2 months ago 9
Android Question

Android: can I use one SQLiteOpenHelper class for multiple database files?

My app uses two databases (separate files). To handle these databases I have created two Helper classes which extend SQLiteOpenHelper, one for each database.

I am now going to add a third database and wonder whether I need to create yet another Helper class (and if I used a 4th and a 5th database would I need even more Helper classes), or can I use the same Helper class for multiple databases?

The problem that I see with trying to use just one Helper class is that I can't see how to pass the name of the individual database files to the Helper. At present the name of the database is hard-coded as a Static field of each of the Helper classes, but if I had only one Helper class I would need to be able to pass the different names in to the Constructor when creating the separate Helper objects; the problem is that the SQLiteOpenHelper Constructor seems to be called by Android with just one parameter: the Context.

Answer

Of course, you can. It is just a matter of your Helper class design. You can just pass the name of DB to your Helper class constructor (along with required Context instance) instead of hardcoding:

public class DBOpenHelper extends SQLiteOpenHelper {

    public DBOpenHelper(Context context, String dbName, int dbVersion) {
        super(context, dbName, null, dbVersion);
    }
...
}