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C# Querying With LINQ Querying the BirdWatcher Data Sightings of Endangered Birds

Aaron Selonke
Aaron Selonke
10,323 Points
Posted by Aaron Selonke
Aaron Selonke
10,323 Points

What was that!

Why do the groupings return { Status = Vulnerable, Sightings = System.Collections.G eneric.List`1[BirdWatcher.Sighting] }

when calling the Count(), what exactly is being counted?

1 Answer

Matthew Hill
Matthew Hill
7,799 Points
Matthew Hill
Matthew Hill
7,799 Points

When the results of the first query are grouped by status, all of the sightings associated with that status are turned into a list. So if you have:

Endagered - 1 sighting Endagered - 3 sightings Endagered - 2 sightings

You end up with:

Endagered - 1 sighting, 3 sightings, 2 sightings

As for your second question. Remember that sighting is a class in and of itself. This means that in the bird class it is represented as a list of sightings. You therefore need to do a count on the list for each bird in the group, then sum those together.

Hope that makes sense! Matt