title: Best way to handle unique constraints when using Entity Framework
body: <p>I'm using Entity Framework 4.0 to access data in a table with a unique column constraint.  If the constraint is violated, an exception occurs when I call SaveChanges(), as expected.  My question is whether I should allow the exception to be thrown in the first place.  I could alternatively do a select to avoid inserting the duplicate data (I assume a transaction would be necessary).</p>
  
  <p>What's the generally accepted best practice in this scenario?</p>