Summing up

Run this example using its test data from within FlightPath Data.

~
   This csvpath sums up two header values in a similar way to this SQL.
	SELECT
	  SUM (CASE
	    WHEN neighborhood IN ('Roxbury','South Boston')
	    THEN worker_hours_this_period
	    ELSE 0 END) AS roxbury_south_boston_hours,
	  SUM (CASE
	    WHEN trade IN ('Iron Worker','Pipefitter')
	    THEN worker_hours_this_period
	    ELSE 0 END) AS iron_worker_pipefitter_hours
	FROM projects

   id: hello world
   test-data: examples/counting/projects.csv
~
$[1*][
	subtotal.neighborhood(#neighborhood, #worker_hours_this_period)
	subtotal.trade(#trade, #worker_hours_this_period)

	@trade_hours = add( get("neighborhood", "Roxbury"), get("neighborhood", "South Boston") )
	@neighborhood_hours = add( get("trade", "Iron Worker"), get("trade", "Pipefitter") )

	last() -> replace( #neighborhood, @neighborhood_hours )
	last() -> replace( #trade, @trade_hours )
	last() -> collect( "neighborhood", "trade" )
	last() -> print("Check out the matches tab")
]