Realm, ObjectBox or Room. Which one is for you?
Database relations with Room [ https://medium.com/androiddevelopers/database-relations-with-room-544ab95e4542 ]
Offline App with RxJava 2 and Room
SQLite Triggers (+ Android Room) [ https://proandroiddev.com/sqlite-triggers-android-room-2e7120bb3e3a ]