title: create inner join between field not mapped with a field in database in Entity Framework
body: <p>How do I create a relationship between fields  DecodePersonnelID and PersonnelID Field</p>
  
  <pre><code>public partial class MyUser
  {
  public int UsersID { get; set; }
  public string PersonnelID { get; set; }
  [NotMapped]
  public int DecodePersonnelID
  {
      get { return DecodeMD5PersonnelID(PersonnelID); }
      set { PersonnelID = EncodeMD5(value.ToString() ); }
  }
  public string UsersName { get; set; }
  }
  public partial class Personnel
  {
  public int PersonnelID { get; set; }
  public string FirstNameFa { get; set; }
  public string LastNameFa { get; set; }
  public bool Gender { get; set; }
  }
  
  
  RAYANContext db=new RAYANContext();
          var query = (from m in db.MyUsers
                       join p in db.Personnels on m.DecodePersonnelID equals p.PersonnelID
                       select new
                       {
                           m.UsersName,
                           p.FirstNameEn
                       }).ToList();
  </code></pre>
  
  <p>Error:The specified type member 'DecodePersonnelID' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.</p>