Does EF have ordered collections? The equivalent of list in the NHibernate Bag Vs Set Vs List world

Question

Does the Entity Framework 4 have ordered collections?

For example my Order has a property that is a collection of OrderItems, but the order is important and I would rather not sort them before I access them.

See Nhibernate for an example: List vs Set vs Bag in NHibernate

score 4 · Accepted Answer · edited May 23 '17 at 12:01

4

It doesn't. You can force an order in a couple of ways however :

This answer explains one EF4 LINQ Ordering Parent and all child collections with Eager Loading (.Include()) (kind of)

More simply, if you are querying a single order, you can do so with the orderlines ordered in a specifc way:

var thing = _repo.GetOrder(id)
 .Select(item => 
    new { item, ord = item.orderlines.OrderBy(o => o.orderbythis) }
    ).FirstOrDefault().item;

edited May 23 '17 at 12:01

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answered Jan 14 '11 at 22:40

Andiih

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keep in mind this will return an "item" without the "ord" - you havent't assigned the "ord" anonymous property back into the projected type. – RPM1984 Jan 14 '11 at 23:19
Yes I know. However item.orderlines IS ordered in the specified manner. I guess there is a danger this may break in future releases, but it does work! If anyone can explain why this works I'd love to know! – Andiih Jan 15 '11 at 12:13

Does EF have ordered collections? The equivalent of list in the NHibernate Bag Vs Set Vs List world

1 Answers1