If I run a Room migration with destructive fallback enabled:
Room.databaseBuilder(applicationContext, MyDb::class.java, "database-name")
.fallbackToDestructiveMigration()
.build()
Is there a way to determine if the destructive migration was triggered vs if the migration completed successfully? I'd like to be able to log some information for tracking.
You can use use Room Callback and add it to your database, it has below methods: where you can use onDestructiveMigration
Here is a sample example
@Database(entities = {.....}, version = 1)
public abstract class MyDatabase extends RoomDatabase {
private static final String DATABASE_NAME = “myDatabaseName.db”;
private static final Object LOCK = new Object();
private static volatile MyDatabase instance;
public static MyDatabase getDatabase(final Context context) {
if (INSTANCE == null) {
synchronized (MyDatabase.class) {
if (INSTANCE == null) {
// Create database here.
INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
MyDatabase.class, DATABASE_NAME)
.fallbackToDestructiveMigration()
.addCallback(mCallback) // Trigger the callback
.build();
}
}
}
return INSTANCE;
}
/*
* Callback when database is created & when it’s opened
* */
static RoomDatabase.Callback mCallback = new Callback() {
@Override
public void onCreate(@NonNull SupportSQLiteDatabase db) { // Callback when database is first-time created or recreated after destruction
super.onCreate(db);
Log.i("LOG_TAG", “Database is created”);
}
@Override
public void onOpen(@NonNull SupportSQLiteDatabase db) { // callback when the activity is opened
super.onOpen(db);
Log.i("LOG_TAG", “Database is opened”);
}
};
@Override
public void onDestructiveMigration(@NonNull SupportSQLiteDatabase db) { // Called after the database was destructively migrated
super.onDestructiveMigration(db);
Log.i(LOG_TAG, “Database is destructed”);
}
}