The Android and Firebase code given in this course is correct, but it may not work for current SDK or API because of the backward compatibility issue. You should be able to fix it by checking the error messages.

Slide 8.1: Introduction to Firebase database (video: 2:34 & 1:56 minutes) Slide 8.2: SQL vs NoSQL Slide 8.3: Using Firebase database (Android) Slide 8.4: Structuring Firebase Slide 8.5: Writing data to Firebase Slide 8.6: Writing data to Firebase (cont.) Slide 8.7: Reading data from Firebase Slide 8.8: Deleting and updating data in Firebase Slide 8.9: A Firebase mobile app Slide 8.10: A Firebase mobile app (cont.) Slide 8.11: The manifest file Slide 8.12: The layout file Slide 8.13: The values folder Slide 8.14: The Java program, MainActivity.java Slide 8.15: The Java program, MainActivity.java (cont.) Slide 8.16: The Java program, MainActivity.java (cont.) Slide 8.17: The Java program, MainActivity.java (cont.) Slide 8.18: The Java program, MainActivity.java (cont.) Slide 8.19: The Java program, User.java   ☂ References Slide 8.a: Firebase app construction (video: 56:15 minutes) Slide 8.b: Firebase Slide 8.c: Firebase CRUD Slide 8.d: Firebase tutorial