Conditional Record Delete in a Loop

Question

Can someone explain how to conditionally delete objects from an EF result set?

Here is my code

var newClubKitOrders = from q in db.NewClubKitOrders where q.NewClubId == ncbId select q;
if (newClubKitOrders.Any())
{
    foreach (NewClubKitOrder order in newClubKitOrders)
    {
        if (checkedStatus == true)
        {
            order.OrderDate = DateTime.Now;
        }
        else
        {
            //delete the row (order.delete())
        }
    }

   newClubKitOrders.SaveChanges();
}

Thanks

http://stackoverflow.com/questions/17723626/entity-framework-remove-vs-deleteobject — T McKeown, Jun 13 '14 at 18:03

score 4 · Answer 1 · answered Jun 13 '14 at 18:01

4

You can't delete 'order' in “foreach” loop. So try “for” loop.

answered Jun 13 '14 at 18:01

Arik

180
2
9

This seems to not cause any warnings inside foreach() in VS but not sure if it actually deletes yet: var success = newClubKitOrders.Remove(order); – Slinky Jun 13 '14 at 18:05
@Slinky It'll compile, but when you go to run it it'll complain that the enumeration had changed. – sab669 Jun 13 '14 at 20:18

score 0 · Answer 2 · edited May 23 '17 at 12:27

0

Use DeleteObject

Like this:

        else
        {
           newClubKitOrders.DeleteObject(order);
        }

Here is a good SO on some other options and how it all works.

Edit: Also yes, use a for loop, I didn't notice what you were iterating over. Thanks Rashmin Javiya!

edited May 23 '17 at 12:27

Community

1
1

answered Jun 13 '14 at 18:00

TheNorthWes

2,661
19
35

score 0 · Answer 3 · answered Jun 13 '14 at 18:06

Try following code, i have copied list in another list to be on safe side. temp list is just to traverse but actual transaction take place on original list

var newClubKitOrders = from q in db.NewClubKitOrders where q.NewClubId == ncbId select q;

if (newClubKitOrders.Any())
{
    var TempnewClubKitOrders = newClubKitOrders.ToList();

    for(int i=0; i< TempnewClubKitOrders.Length; i++)
    {
        if (checkedStatus == true)
        {
            newClubKitOrders[i].OrderDate = DateTime.Now;
        }
        else
        {
            db.NewClubKitOrde.DeleteObject(newClubKitOrders[i]);
        }
    }

   db.SaveChanges();
}

Error: "Cannot apply indexing to linq expression.." I guess I cannot use array indexer for some reason - seems odd since it was converted to a list — Slinky, Jun 13 '14 at 18:15

score 0 · Answer 4 · answered Jun 13 '14 at 20:18

this should work:

var newClubKitOrders = from q in db.NewClubKitOrders where q.NewClubId == ncbId select q;

if (newClubKitOrders.Any())
{
    foreach (NewClubKitOrder order in newClubKitOrders)
    {
        if (checkedStatus == true)
        {
            order.OrderDate = DateTime.Now;
        }
        else
        {
            db.NewClubKitOrders.Remove(order);
        }
    }

    db.SaveChanges();
}

Conditional Record Delete in a Loop

4 Answers4