How to solve field wrapping in Entity Framework database-first

Question

When I use database first, after creating the edmx file, all the conceptual models have already been generated. But I want to do some special operations on certain fields. For example, there's a field named 'price'; I want the matching property 'Price' to return double of the 'price'. How can I do that? If I modify the getter in the code, every time I update the model from database, all of the modifications go away.

What's the correct way to do this?

Answer 1

What you can do is create a partial class for entity which contains the Price Property and put a getter like this (A property with double price will be meaningful ),

Public partial class YourEntity{
  Public float DoublePrice{
    get { return Price*2;}
 }
}

Or you can create a class inherited from the entity,

 Public partial class Entity:YourEntity{
      Public override float Price{
        get { return base.Price*2;}
     }
  }