How delete collection?

Question

 var main = (from d in db.Discounts where d.Id == discount.Id && d.UserId == userId select d).FirstOrDefault();
main.Address = "new address";
main.TermsStocks.Clear(); // I need clear collection and add new object.

            foreach (var termsStock in terms)
            {
                main.TermsStocks.Add(new TermsStock() { Id = Guid.NewGuid(), MainId = main.Id, Title = termsStock.Title });
            }
db.SaveChanges();

and I have error:

The operation failed. Unable to change the link because one or more properties of the foreign key values do not allow NULL. If you change the connection property of the respective foreign key set to NULL. If the foreign key value does not support NULL, must be defined a new relationship, the foreign key property should be set to another value other than NULL, or to remove unbound object.

how to remove the entire collection and save a new one?

possible duplicate of [Entity Framework 4 Delete Object from entity collection](http://stackoverflow.com/questions/4922228/entity-framework-4-delete-object-from-entity-collection) — Ladislav Mrnka, Apr 02 '12 at 08:03

score 1 · Accepted Answer · answered Apr 02 '12 at 08:03

1

You will have to remove those items form the database as well, not just from the nav property.

Roughly:

// main.TermsStocks.Clear(); 
foreach (var item in main.TermsStocks)
{
    db.TermsStocks.Remove(item);
}

answered Apr 02 '12 at 08:03

H H

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score 0 · Answer 2 · answered Apr 02 '12 at 08:13

0

I think TermsStock object has a non nullable foreign key of Discount. Then it is not possible to have a TermsStock object without a Discount. What you are trying to do is not possible in this manner.

answered Apr 02 '12 at 08:13

daryal

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How delete collection?

2 Answers2