Why use UID in Firebase? Should I use it

Question

I know UID is used because it is unique. But in my app, all of them are registered with Google ID, Google ID is also unique. Should I use UID?

Answer 1

yes it is better to use the uid. From the docs:

You can let your users authenticate with Firebase using their Google Accounts by integrating Google Sign-In into your app.

So after you authenticate the users, the uid will be in the authentication page in firebase. That id will help you later in the firebase database also and it is easier to use and add in the database.

Can easily be gotten using this:

 FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();

Then you can use the method getUid() to get the userid. So using it will make the work easier for you.

From the docs:

After a user signs in for the first time, a new user account is created and linked to the credentials—that is, the user name and password, phone number, or auth provider information—the user signed in with. This new account is stored as part of your Firebase project, and can be used to identify a user across every app in your project, regardless of how the user signs in.

Also check this link: https://firebase.google.com/docs/auth/android/google-signin (Next Step section)