Facebook Canvas App - Finding all users who have installed the app

How do I find out all users who have installed my canvas app ? Is there a U开发者_Python百科I on Facebook for it or do I need to query an API ?

See https://developers.facebook.com/docs/reference/fql/insights/#Metrics

You can check the application_installed_users value to figure out how many users have installed your app.

EDIT: this requires the use of the Facebook FQL interface, as covered at https://developers.facebook.com/docs/reference/fql/

It can't be done as per this - How to get all the user IDs of people who are using your Facebook application

I would suggest use you to use the depreceated REST API call once to save all the IDs of the users, and then add a new user to that list (keep on saving it in a db).