Best way to implement “ReOrderable Collection” and Persist it to database

Question

My domain object :

public class MyDomainObject
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public int DisplayOrder { get; set         


        

Answer 1

I answered a previous/similar question about re-ordering here: How to design table that can be re-sequenced?

This does a good job of resaving the Order with no gaps. Depending on the size the lists resaving the Order may be a perfectly viable option, for long lists Mark Byers' idea looks pretty good.