Question

I want users to be able to login from any provider (facebook, google, etc) from my app and also to create an account with my server. What I want to figure out is the best way to construct a user model doing this.

For example,

A user logs in using facebook a new user record will be made and there will be a flag in the record telling me that the account is a facebook account. If the same user creates a standard account with my server and then logs back in using facebook, how shall I handle this? Is the best practice to merge/relate these two accounts with each other or to treat them as two different records?

Answer 1

Currently Im working on the same things. I will use these rules:

• Check emails. Its be best way to identify user.
• Set special long-time cookie after successful registration. Later you can ask user to merge
  accounts.
• Username, realname, birthday etc can be used as additional
  params to compare.

About scheme: I create a table users (id, username, email) and user_data (id, user_id, email, service_id, service_name, service_type, is_active). service_id is a Provider-specific identifier, service_type is a Provider name (google/facebook/etc), and service_name is a displayName from Provider’s site (may differs from user.username). service_id + service_type must be unique.