Entity framework relations issue

Question

I have been working for a while now with EF and I prefer code first approach where it allows you to have more in hand. Now I have been working on a not so big project but yet I came across some bumps (inheritance issues was one of them). Now I have tried several ways (annotations, Fluent API) but my problem just gives another error/exception message so this is why I am here to ask your suggestions/help.

I have the following entities :

YogaClass

public class YogaClass
    {
      [Key]
      public int YogaClassID { get; set; }
      public virtual List<YogaClassSubscription> YogaClassSubscribtions {get; set;}
}

Workshop

public class Workshop
    {
        [Key]
       public int WorkShopID { get; set; }
       public virtual List<WorkshopSubscription> WorkshopSubscribtions { get; set;}
}

YogaClassSubscription

public class YogaClassSubscription
    {
        [Key]
        public int YogaClassSubscriptionID { get; set; }

        [Required]
        public virtual Account Account { get; set; }

        //[ForeignKey("Account")]
        //public int AccountID { get; set; }

        [Required]
        public virtual YogaClass YogaClass { get; set; }
}

WorkshopSubscription

 public class WorkshopSubscription
    {
        [Key]
        public int WorkshopSubscriptionID { get; set; }

        [Required]
        public virtual Account Account { get; set; }

        //[ForeignKey("Account")]
        //public int AccountID { get; set; }

        [Required]
        public virtual Workshop Workshop { get; set; }
}

Account

public class Account
    {
    [Key]
    public int AccountID { get; set; }
    public virtual List<YogaClassSubscription> YogaClassSubscriptions { get; set; }
    public virtual List<WorkshopSubscription> WorkshopSubscriptions { get; set; }

}

Where : YogaClassSubscription has a required YogaClass & a required Account WorkshopSubscription has a required Workshop & a required Account Account has a List & List which are not required.

When i seed i create following entities: Account1 , Workshop1 , YogaClass1 , YogaClassSubscription1 (which has YogaClass1 & Account1) & WorkshopSubscription1 (which has Workshop1 & Account1)

The seeding goes as expected, but when addressing the database for the first time it fails on creating the database itself.

Seems EF can't map the database correctly, I tried setting a property int AccountID in YogaClassSubscription & WorkshopSubscription class referring it as a foreign key (annotation and fluent API) but the issue persists.

Fluent API

modelBuilder.Entity<YogaClassSubscription>()
.HasRequired<Account>(ycs => ycs.Account)    
.WithMany(ycs => ycs.YogaClassSubscriptions)
.HasForeignKey(ycs => ycs.AccountID); 

I have tried to give a temp ID to the account (in the seeder) so that EF could make difference between the 2 instances of Account that I am referring but this still won't work (that solved it for somebody else).

I'm kind of lost, I get that

1) EF can't make a distinction between the beginning and end of an association using the required annotation on account, in both subscriptions (which should work since an account doesn't necessary have subscriptions but any subscription should have an account).

2) That there are 2 instances that have the same FK (from the account) which is normal but since it's not inserted yet (having any ID) it can't make a difference apparently.

When I don't use any annotation, or the fluent API leaving the properties virtual, it creates the database but then the table which should refer to the accountID is null.

So I don't know what to do for EF to map it correctly. I have tried lots of answers proposed from StackOverflow regarding the errors I get but none of them resolved my issue.

Thank you in advance for any suggestion or help ! Kind regards

Answer 1

Ok so i feel akward , after a night of sleep, i started to think and well, i first had a base class Subscription which WorkshopSubscription & YogaClassSubscription inherrited from.

After having several issues i decided to leave the base class Subscription out and continue without it. Of course silly me i still had those ctors which wheren't setting the account because they where set in the base class so yeah, there you go, added the entities in ctor fixed my issue. Thank you Kim Hoang for your time and suggestion !

Kind regards