Delete item from database but not other item related to this

Question

I have this in my Article class:

    public int GalleryID { get; set; }
    public virtual Gallery Gallery { get; set; }

and this is my gallery class:

public class Gallery
{

    public int GalleryId { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Photo> Photos { get; set; }
}

when I delete gallery by this in repository:

    public virtual void Delete(int id)
    {
        T entity = dbset.Find(id);
        dbset.Remove(entity);
        dataContext.SaveChanges();
    }

I deleted article too but that isn´t what I want. I want to keep article (just maybe set galleryId to 0 a and gallery to null. Thanks

How does your question relate to ASP.NET MVC3? It looks more like you are asking about how to use some ORM (which by the way you haven't specified in your question). Is it EF or something? Please use proper tags. — Darin Dimitrov, Apr 17 '12 at 07:50

score 1 · Answer 1 · edited May 23 '17 at 11:49

1

In your artical make the foreign key nullable

public int? GalleryID { get; set; }

On delete of the gallery, you need to clear its article collection

public void DeleteGallery(int id)
{
    var entity = dataContext.Galleries
                .Include(e => e.Articles)  // include your child object collection
                .First(e => e.Id == id);

    dataContext.Galleries.Articles.Clear();  // this removes the reference to the parent
    dataContext.Galleries.Remove(entity);

    dataContext.SaveChanges();
}

see here EF 4.1 RC: Weird Cascade Delete

edited May 23 '17 at 11:49

Community

1
1

answered Apr 17 '12 at 07:53

Anthony Johnston

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This might help but now I have this problem: "The primary key value cannot be deleted because references to this key still exist. [ Foreign key constraint name = FK_Articles_Galleries_GalleryID ]" – Libor Zapletal Apr 17 '12 at 08:01
are you using code first fluent api? how are you specifying the FK? – Anthony Johnston Apr 17 '12 at 08:05
For now code in classes was just enough. Can you help me with what I shoudl add to ´protected override void OnModelCreating(DbModelBuilder modelBuilder)´ ? – Libor Zapletal Apr 17 '12 at 08:17
you will need to remove the parent child relationship from the child, see above – Anthony Johnston Apr 17 '12 at 09:06

Delete item from database but not other item related to this

1 Answers1