I'm writing a query that uses FirstOrDefault
after an OrderBy
query, which should check if it isn't null first then use some data in it. Is there a better way than writing it like this:
int count = db.Items.Count(i =>
i.Assignments.OrderByDescending(a =>
a.DateAssigned).FirstOrDefault() != null
&&
i.Assignments.OrderByDescending(a =>
a.DateAssigned).FirstOrDefault().DateReturned == null)
What this code does is there are items that has many assignments, I take the latest assignment by date, then check if it exist, then run a condition on a property (DateReturned
). As you see, this query is long, and most of my queries seem to look like this where I check for null first then run a second query on it using their properties. Is there a better way of doing this?
Just call .Any(a => a.DateReturned == null)
to check whether there are any items that meet the condition.
If you only want to check the latest assignment, add .Take(1)
before the .Any()
.
My take:
int count =
itemsQuery.Select(i => i.Assignments.OrderByDescending(a => a.DateAssigned))
.Count(i => i.FirstOrDefault() != null &&
i.First().DateReturned == null);