Question

I have a project with classes in a project that I am building in a Code First style. The problem is simple. The objects in question are a User and a userType.

public class User
{
    [Key]
    public int id { get; set; }

    [DisplayName("User Name")]
    [Required(ErrorMessage = "User Name is required.")]
    public string userName { get; set; }

    [DataType(DataType.Password)]
    [DisplayName("Password")]
    [Required(ErrorMessage = "Password is required.")]
    public string userPassword { get; set; }

    [DisplayName("First Name")]
    public string first_Name { get; set; }

    [DisplayName("Last Name")]
    public string last_Name { get; set; }

    [DisplayName("Email")]
    public string email { get; set; }

    [DisplayName("Zip")]
    public string Zip { get; set; }

    [DisplayName("Address")]
    public Address address { get; set; }

    [DisplayName("Birthdate")]
    public DateTime dateOfBirth { get; set; }

    [DisplayName("Home phone")]
    public string homePhone { get; set; }

    [DisplayName("Cell phone")]
    public string cellPhone { get; set; }

    [DisplayName("Remember me")]
    public bool persistCookie { get; set; }

    public UserType userType { get; set; }

    public int status { get; set; }

}

AND

public class UserType
{
    [Key]
    public int id { get; set; }
    public string typeName { get; set; }

}

I generate a User like this:

userType = (from ret in db.UserTypes where ret.typeName.Equals("Contractor") select ret).FirstOrDefault();
                user.userType = userType;
                user.status = 1;
                db.Users.Add(user);
                db.SaveChanges();

The database schema seems to support the foreign key to the UserTypes table.

Everything works well on the add and in the database I see a user record with the appropriate userType_id.

The problem comes when I retrieve the user later on. My User.userType is always null. This has me really confused. If the userType key is in the Users table for the record, why do I not get a userType object as part of my User when I get that user using a standard LINQ query like:

User user = (from ret in db.Users where ret.userName.Equals(userIn.userName) && ret.userPassword.Equals(userIn.userPassword) select ret).FirstOrDefault();

I get the User but user.userType is always null.

What am I missing here?
Should I be building a different LINQ query?
Shouldn’t the userType object be automatically included in the User object?

I think the Code First programming style is an excellent methodology but this problem has me baffled.

Thanks for any help!

Answer 1

You need to tell EF to eager load the navigational property userType by using Include method.

User user = (from ret in db.Users.Include(u => u.userType)
             where ret.userName == userIn.userName 
             && ret.userPassword == userIn.userPassword select ret)
             .FirstOrDefault();

Or make the userType property virtual so that EF will lazy load it.

public virtual  UserType userType { get; set; }