I just updated the entityframework to the latest 5.0.0 version. And the NotMapped annotation doesn't work now. I tried to google for an answer to fix it but couldn't find. Anyone had the same problem when you updated the entityframework and know a solution to fix this problem?
Annotation attributes in EF 5.0 with .NET 4.5 were moved to System.ComponentModel.DataAnnotations assembly and System.ComponentModel.DataAnnotations.Schema namespace.
[NotMapped] is in System.ComponentModel.DataAnnotations.Schema. Make sure to add using System.ComponentModel.DataAnnotations.Schema; to your code.
来源：https://stackoverflow.com/questions/12194267/updated-to-ef5-now-notmapped-annotation-doesnt-work