Android Question Firebase Auth

Stefano Di Chiano

Active Member
Licensed User
I'm using firebase auth to enable login with Google and Facebook. My aim is to make users decide one way to sign in (Facebook or Google) and use that every time they use my app. Once they do the log in, I take the email and username and register them on my database.

To do this, there is an option on the Firebase console, this one to be clear:

I opted for "Prevent creation of multiple acounts with the same email address" since it's exactly what I want to do, but I'm having some troubles.

The first thing is that while Google asks me what account I want to sign in with, Facebook only does it the first time, even if I delete the account on Firebase console. So if for some reason I'd want to sign in with a different Facebook account, I couldn't.

Second issue is: if I sign in with Google and the next time I try to sign in with Facebook, the login will not be successful and I'll receive an error. The problem is that it is not true the other way around.
If the first time I use my Facebook account and the second time my Google account, Firebase will allow it and delete the Facebook account on the console.

So, since my final aim is to register the user on my database, I allowed the creation of multiple accounts with the same email address to make further controls on the access way later, but if I choose this option, when I sign in with either Facebook or Google, it will not get the user email and
shows nothing.

How should I deal with this behavior? I don't see other settings on the console that could help me with this matter.