title: entity framework 4 many to many update
body: <p>I have 3 tables - </p>
  
  <pre><code>User (Id, Name)
  Roles (Id, Name)
  UserRoles (UserId, RoleId)
  </code></pre>
  
  <p>I think they are self explanatory. How do I update an entry (UserId and RoleId) in UserRoles?</p>
  
  <p><code>context.User.Roles</code> gives me the list of roles but how do I update them?</p>
  
  <p>Thank you.</p>