Room2.java

@Database(entities = { WeatherEntry.class , UserEntry.class}, version = 2)
//any change to tables .. you must increase version, and define a migration methodology
@TypeConverters(DateConverter.class)
public abstract class SunshineDatabase extends RoomDatabase {

...

public static SunshineDatabase getInstance(Context context) {
  if (sInstance == null) {
    synchronized (LOCK) {
      if (sInstance == null) {
        sInstance = Room.databaseBuilder(context.getApplicationContext(), SunshineDatabase.class,
            SunshineDatabase.DATABASE_NAME)
            .fallbackToDestructiveMigration() //recreate all tables
            .build();
      }
    }
  }
  return sInstance;
}

public abstract WeatherDao weatherDao();

//this is another Dao, I created to experiment
// if It's needed to create a Room database for each DAO
//well nope, but you need to define your entities in  @Database(Class[] entities)
public abstract UserDao userDao();