Linq expression with eager loading only top n records

Question

I am using entity framework core. I am eager loading a navigation property for an entity. What I want to achieve here is only load top 5 records ordered by creation date along with the main entity. I have following query.

Context.Foo.Where(f => f.Id == fid)
    .Include(f1 => f1.Bars.OrderByDescending(b => b.CreateDate).Take(LIMIT))
    .FirstOrDefault();

It throws error that property expression is not valid. I understood that the expression should just evaluate to a property we want to include, but is there a way where we can fine tune the selection of properties?

As per the accepted answer on "How to filter “Include” entities in entity framework?" It is currently not supported by EF — Chaitanya Gadkari, Feb 02 '18 at 11:10

score 0 · Accepted Answer · answered Feb 01 '18 at 15:10

0

Filtering includes is not allowed in EF Core to the best on my knowledge. It does look like there is a github project that adds this feature which may work in your case. https://github.com/zzzprojects/EntityFramework-Plus/wiki/EF-Query-IncludeFilter-%7C-Entity-Framework-Include-Related-Entities-using-Where-Filter

answered Feb 01 '18 at 15:10

Zackary Ridall

41
3

Even though this is not what I am looking for, at the moment EF do not support the feature, so accepting this answer as its most suitable for now – Chaitanya Gadkari Feb 14 '18 at 09:10

Linq expression with eager loading only top n records

1 Answers1