title: Entity Framework Override of Abstract Property Not Saved
body: <p>I'm using EF5 Code First. I have a base class that includes an abstract property as such:</p>
  
  <pre><code>public abstract class BaseTransaction : EntityBase
  {
      [Required]
      public int PolicyId { get; set; }
      public virtual Policy Policy { get; set; }
  
      public DateTime EffectiveDate { get; set; }
      public string Description { get; set; }
  
      public abstract double Premium { get; set; }
      public double Commission
      {
          get
          {
              return Premium * Policy.CommissionRate / 100;
          }
      }
  }
  </code></pre>
  
  <p>I have several different descendant classes, each of which defines Premium differently. For some it simply stored with the class, for others it might be read only computed.</p>
  
  <p>For example:</p>
  
  <pre><code>public class ManualQuote : BaseTransaction 
  {
      public double Deductible { get; set; }
      public double ClaimLimit { get; set; }
      public double AggLimit { get; set; }
      public override double Premium { get; set; }
  }
  </code></pre>
  
  <p>When I save a ManualQuote to the database, the first three properties are save to fields correctly. However, the data for Premium property is not save.  Am I doing something incorrectly or is this an issue with Entity Framework?</p>
  
  <p>Thank you.</p>