CODEWITHSUNDEEP
c#linqentity-framework-core
abolotnov
abolotnov

Reputation: 4332

How to build a Linq Expression for selecting nested objects?

I am using a generic repository to retrieve objects from the database and while lazy loading is not available in EntityFramework Core, sometimes I would need to select related objects.

The repo code looks like this:

public T GetSingle(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] includeProperties)
    {
        IQueryable<T> query = _context.Set<T>();
        foreach (var includeProperty in includeProperties)
        {
            query = query.Include(includeProperty);
        }

        return query.Where(predicate).FirstOrDefault();
    }

and telling it to select a related object is simple:

.GetSingle(id,x=>x.ObjectviaFK)`

I can't wrap my head around building an expression that will allow selecting nested objects (similar to .Include(...).ThenInclude(...) from context), something like .GetSingle(id, x=>Parent,parent=>Grand,grand=>GrandGrand). How do I do this?

Upvotes: 0

Views: 579

Answers (1)

NetMage
NetMage

Reputation: 26936

It would seem if you don't want to change your GetSingle you could just put in the correct lambdas to include the nested objects?

`.GetSingle(id, x=>x.Parent, x=>x.Parent.Grand, x=>x.Parent.GrandGrand)

Upvotes: 1

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