How to populate Android Room database table on first run?

Question

In SQLiteOpenHelper there is a onCreate(SQLiteDatabase ...) method which i used to populate database tables with some initial data.

Answer 1

I tried a number of ways to do this, each to no available.

First, I tried adding a Migration implementation to Room using the 'addMigrations' method, but found that it only runs during a database upgrade, but not on creation.

Then, I tried passing a SQLiteOpenHelper implementation to Room using the 'openHelperFactory' method. But after creating a bunch of classes in order to get around Room's package-level access modifiers, I abandoned the effort. I also tried subclassing Room's FrameworkSQLiteOpenHelperFactory but, again, the package-level access modifier of its constructor didn't support this.

Finally, I created a IntentService to populate the data and invoked it from the onCreate method of my Application subclass. The approach works but a better solution should be the upcoming fix to the tracker issue mentioned by Sinigami elsewhere on this page.

Darryl

[Added July 19, 2017]

The issue looks as though it's resolved in Room 1.0.0. Alpha 5. This release added a callback to RoomDatabase that lets you execute code when the database is first created. Take a look at:

https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase.Callback.html