title: Handling Multiple Social Login/Registration System
body: <p>First let me clarify what am not asking. Am not asking how to do the Registration/Login itself. I can use OAuth with Twitter and FB for example, to register single user.</p>
  
  <p>Now what am asking:
  I have user table and socials table which holds user registration. When user tries to register with his social network, we also present a form for his "user" table information (Like birth-date) and then log him immediately. So far so good! Now Suppose <em>user logs out</em> and somehow this time <em>logs in with Twitter</em>. How should I connect the "user" table data since I have no idea its the same user already have registered?</p>
  
  <p>I could use email, but some people have different email for Facebook and Twitter Account. In that case I will have duplicate profiles in "user" table. I know I can tell user to login and associate his social account with his twitter or create new profile. But am trying to check if there is anything I can do to associate user Twitter profile with same data in "user" table that user filled in when he used facebook</p>