title: EntityFramework how to Override properties
body: <p>I've just started using EF in VS2010. That thing is just amazin'.</p>
  
  <p>I frankly can't understand something. For example I have EntityType with property, they generated from database structure. 
  Now, I have to simply override that property in my code. I don't need to save value of the property back into DB, but everytime when it gets read from DB it should be substituted with run-time calculated value.  </p>
  
  <p>Of course I can create derived class based on my EntityType but I've tried and found kinda difficulties, I'm not sure this is kinda right way to do. Anyway even when I try to change the  whole EntityType to Abstract, damn Visual Studio doesn't want to validate that and says something like: </p>
  
  <p>"Error 2078: The EntityType 'AssetsModel.Asset' is Abstract and can be mapped only using IsTypeOf."
  "Error 2063: At least one property must be mapped in the set mapping for 'Assets'"</p>
  
  <p>What the hell is this suppose to mean I dunno..</p>
  
  <p>Any ideas? </p>