Hi Developers, 

I'm trying to get a linq query running which I can't get right.

I have a list of a custom class called Occurrences, this class has two properties Code as String and Negative as Boolean. I am trying to get the net total of Code (group by Code) so this would be a count of Code where Negative = False (All positive), subtract a count of Code where Negative = True (All negative). There is no quantity in the Occurrences class, each occurrence counts as 1 negative or positive.

I tried to do this in 3 separate queries which did not work, ideally I would like to do this in 1 query.

Please let me know if you need a better explanation or if I am unclear.

Edit: Sample input/output

Input:

Code       Negative

-------------------

123        True

123        True

123        False

456        True

456        True

456        True

789        False

789        False

Output:

Code       Count

----------------

123        -1

456        -3

789        +2

Any help on above is really appreciated.