Unable to determine the relationship represented by navigation property 'JToken.Parent' of type 'JContainer'

Question

I am using the 'Asp.Net Core 2.0' and installed nuget package 'Microsoft.EntityFrameworkCore' version '3.0.0-preview5.19227.1', when I want to use a IQuarable functions, I get the above Error.

    public partial class Wfuser
    {
        public Wfuser()
        {
            UserRole = new HashSet<UserRole>();
        }

        public int IdUser { get; set; }
        public string FullName { get; set; }
        public string UserName { get; set; }

        public virtual Userauth Userauth { get; set; }
        public virtual ICollection<UserRole> UserRole { get; set; }
    }

   public class NormalUser : IUser
    {
        public string UserName { get; set; }
        public string Password { get; set; }
        public NormalUser(string UserName, string Password)
        {
            this.UserName = UserName;
            this.Password = Password;
        }
        public Wfuser CurrentWFUSER { get; set; }
        public string ErrorMessage { get; set; }
        ITTMSContext db;
        public bool IsAuthenticated { get; set; }
        public UserProfile Profile { get; set; }
        public bool Authenticate()
        {
            db = new ITTMSContext();
            CurrentWFUSER = db.Wfuser.FirstOrDefault(u => u.UserName == UserName);
            int idUser = CurrentWFUSER.IdUser;
        }

    }

The full error message was:

'Unable to determine the relationship represented by navigation property 'JToken.Parent' of type 'JContainer'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

Answer 1

我终于独自发现了这一点。 如错误消息所述，我应该在表字段中不在的属性之前添加一个[NotMapped]属性。