title: Entity Framework 4 Single() vs First() vs FirstOrDefault()
body: <p>I'm having a devil of a time finding a comparison of the different ways to query for a single item, and when to use each.</p>
  
  <p>Does anyone have a link that compares all these, or a quick explanation as to why you would use one over the other?  Are there still more operators that I am unaware of?</p>
  
  <p>Thank you.</p>