Question

What is the optimal way to perform the following query?

I have two tables with the following structure:

I want to find all “unowned” assets – where that means there is no AssetOwner record which has the AssetID and either no EndDate or an EndDate in the future.

I have made a first pass at this query:

return from a in db.Assets
       where !db.AssetOwners.Any(o => o.AssetID == a.ID 
                                      && (!o.EndDate.HasValue || o.EndDate > DateTime.Now))
       select a;

But given that I lack experience with this, I want to know whether this is the optimal way to perform this query (I don’t even know what the options are).

Cheers,

Tim.

Answer 1

Pretty good so far. Try

return from a in db.Assets
       where !(a.AssetOwners.Any(o => o.EndDate.HasValue || o.EndDate > DateTime.Now))
       select a;