How to know if a player is already connected

Hi everyone,
Firstly, I'd like to apology for my bad english because i'm a french guy

So, here's my problem :

Is there a way to know if a player is already connected to the game ? I'm making a card game, and, users have to register to play. They connect, and then, they play. But, a user can connect multiple time, and I have try with photon friends to know if I am already connected, but, since I get connect, I am connected... I can't know if there are multiple myself...

So any idea ?

Do i have to make it with my database and some Mysql ?
The problem with Mysql is : if user rage quit (alt + f4) i can't send a message to my database to tell "user with id X leave the game".

This is very problematic, because a player can fight with himself !

Thank you