I have a User
< Country
model. A user belongs to a country, but may not belong to any (null foreign key).
How do I set this up? When I try to insert a user with a null country, it tells me that it cannot be null.
The model is as follows:
public class User{
public int CountryId { get; set; }
public Country Country { get; set; }
}
public class Country{
public List<User> Users {get; set;}
public int CountryId {get; set;}
}
Error: A foreign key value cannot be inserted because a corresponding primary key value does not exist. [ Foreign key constraint name = Country_Users ]"}
You must make your foreign key nullable:
public class User
{
public int Id { get; set; }
public int? CountryId { get; set; }
public virtual Country Country { get; set; }
}