Question

I’ve an object list where each object contains an internal object list and what I would fetching is the father list (left list), however I’m forced to use SelectMany function..Is it possibile?

Naive Example:

var query = objList.SelectMany(p => p.InternalList)
                   .Where(internalObj => internalObj.SomeProprerty == true)
                   .SELECT(objList);

Is there any way to accomplish this?

Answer 1

Assuming you don’t actually want objList, but instead the element of objList which we’re looking at at the time, I think you just want:

var query = objList.SelectMany(p => p.InternalList, (o, p) => new { o, p })
                   .Where(pair => pair.p.SomeProperty)
                   .Select(pair => pair.o);

If that’s not what you’re after, it would really help if you’d give a concrete example.

EDIT: If you only want any example from objList where any element of the internal list has a SomeProperty value of true, you can do that more easily like this:

var value = objList.FirstOrDefault(o => o.InternalList.Any(p => p.SomeProperty));
if (value != null)
{
    ...
}