My collections / model look fine after saving, but when loading entity I do not get the data back out. What am I doing wrong? - entity-framework

Question

Here is my source code for my model:
public class User
{
public User()
{
GUID = Guid.NewGuid();
Account = new Account();
Location = new Location();
}
public long UserID { get; set; }
public Guid GUID { get; set; }
public string DisplayName { get; set; }
public Location Location { get; set; }
public virtual Account Account { get; set; }
}
public class UserConfiguration : EntityTypeConfiguration<User>
{
public UserConfiguration()
{
HasKey(x => x.UserID);
}
}
[ComplexType]
public class Location
{
[MaxLength(2)]
public string CountryCode { get; set; }
[MaxLength(2)]
public string StateCode { get; set; }
public string City { get; set; }
}
public class Account
{
public Account()
{
if (EmailAddresses == null) EmailAddresses = new Collection<EmailAddress>();
}
[ForeignKey("User")]
public long AccountID { get; set; }
public ICollection<EmailAddress> EmailAddresses { get; set; }
public virtual User User { get; set; }
}
public class AccountConfiguration : EntityTypeConfiguration<Account>
{
public AccountConfiguration()
{
HasKey(x => x.AccountID);
HasMany(x => x.EmailAddresses).WithRequired(x => x.Account);
}
}
public class EmailAddress
{
[Key]
public string Email { get; set; }
public EmailTypes Type { get; set; }
public long AccountID { get; set; }
public virtual Account Account { get; set; }
}
public class EmailAddressConfiguration : EntityTypeConfiguration<EmailAddress>
{
public EmailAddressConfiguration()
{
HasKey(x => x.Email);
HasRequired(x => x.Account).WithMany(x => x.EmailAddresses).HasForeignKey(x => x.AccountID);
}
}
And here is my Entity Class:
public class MyEntities : DbContext
{
public MyEntities()
{
Database.SetInitializer<MyEntities>(new DropCreateDatabaseAlways<MyEntities>());
}
public DbSet<User> Users { get; set; }
public DbSet<Account> Accounts { get; set; }
public DbSet<EmailAddress> EmailAddresses { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new UserConfiguration());
modelBuilder.Configurations.Add(new AccountConfiguration());
modelBuilder.Configurations.Add(new EmailAddressConfiguration());
base.OnModelCreating(modelBuilder);
}
}
And finally my code that runs in a test console application:
static void Main(string[] args)
{
var id = CreateUser();
using (MyEntities db = new MyEntities())
{
var a = db.Users.Find(id);
var b = a.Account.EmailAddresses;
var c = db.Accounts.Find(id);
var d = db.EmailAddresses.Where(x => x.Account.AccountID == id).ToList();
}
}
private static long CreateUser()
{
using (MyEntities db = new MyEntities())
{
var u = new User();
u.DisplayName = "TEST";
u.Location.CountryCode = "US";
u.Location.StateCode = "HI";
u.Location.City = "Kauai";
EmailAddress e = new EmailAddress();
e.Email = DateTime.UtcNow.Ticks + "#microsoft.com";
e.Type = EmailTypes.Current;
u.Account.EmailAddresses.Add(e);
db.Users.Add(u);
var cnt = db.SaveChanges();
// Here I get a return of the 4 entities saved, and my model looks correct.
return u.UserID;
}
}
Once the model was saved (CreateUser), I was able to navigate the model and everything looked perfect.
The issue arises when I try to pull the data back out.
My variables:
a -- navigating to email adderess shows 0 records.
b -- this too shows 0 records in the collection.
c -- navigating to email adderess shows 0 records.
d -- here I can get email addresses (but not by navigating the model)

Answer 1

Your test code to access the navigation properties relies on lazy loading. But your Account.EmailAddresses collection is not marked as virtual:
public ICollection<EmailAddress> EmailAddresses { get; set; }
Navigation properties must be virtual (like your User.Account property) in order to make lazy loading possible.
As a side note: I recommend to remove the instantiation of the Account navigation property...
Account = new Account();
...from the User constructor. This is a known source for trouble:
What would cause the Entity Framework to save an unloaded (but lazy loadable) reference over existing data?
EF 4.1 Code First: Why is EF not setting this navigation property?
Instantiating Location is fine because it's a complex type and not a navigation property.