Question

I have a partial class in a dbml file.

public partial class Comment
  string email

Clearly I can’t put a decorator on it because this is a generated file and you shouldn’t make change in it yourself.

So I created another partial class;

public partial class Comment
  [IsEmailAddress]
  string email

The above doesn’t work but I need something like that so I can validate the email address on the model.

Answer 1

You should used MetadataType like so…

[MetadataType(typeof(CommentMetadata))]
public partial class Comment {

}

public class CommentMetadata {
    [IsEmailAddress]
    public string email {get;set;}
}

That will allow you to add your attributes without it being overridden the next time you update your models.