title: Using a class in joining to database table with EF
body: <p>If I have a summary class of some objects I need ( for example its primary key, etc..) is there a way to use a list of that class object when I am writing a joining to other tables? so all the things in my <code>LINQ</code> query are real table like <code>this.Context.MyTable</code>  but one of them be my <code>List&lt;MyClass&gt;</code> ?
  or is there any LINQ related <code>Nuget</code> project that makes this possible?  </p>