Question

I’m trying to use SelectMany to evaluate a first query with conditions, based on those results execute another query. I’ve been told that SelectMany should be able to do this. The problem I’m having is the SelectMany seems to ignore the conditions in the first lambda expression. My problem may be with the first expression but I’m not really sure. Any ideas what I’m doing wrong.

First

  //get source based on user and active flag
  var query = _sourceRepository.GetTable().Where(s => s.ActionItemStates.Any(ais => ais.UserId == user.Id && ais.IsActive == active));  

Second – ignores conditions in first

var queryActionItems = query.SelectMany(x => x.ActionItemStates).OrderBy(x => x.ActionItem.SortOrder);

Answer 1

Well, your first query doesn’t assert that all ActionItemStates will have your userId and IsActive true.

It just mean : select me all the Sources where AT LEAST ONE ActionItemState fulfills my conditions.

But in the second query, ActionItemStates are no longer submitted to your conditions : your just taking all ActionItemStates from the Sources selected in the first query.

First query makes a selection between Sources, not between ActionItemStates.

Now, this is just explaining WHY it doesn’t work, a real answer would need you to explain clearly what you wanna retrieve !