Combine Three Grouped Select Queries Into One - sql

Question

--ON TIME PMWO's
SELECT LOCATION, COUNT(WONUM) AS OnTimePMWOs
FROM
WORKORDER
WHERE worktype = 'pm' and actfinish<=targcompdate
GROUP BY LOCATION
--PAST DUE PMWO'S
SELECT LOCATION, COUNT(WONUM) AS PastDuePMWOs
FROM
WORKORDER
WHERE worktype = 'pm' and actfinish>=targcompdate
GROUP BY LOCATION
--30 DayForecast-
SELECT W.location, COUNT(W.wonum) AS Forecast30days
from
workorder AS W
INNER JOIN PMFORECAST AS P
ON W.CHANGEDATE=P.CHANGEDATE
WHERE WORKTYPE='PM' AND P.forecastdate>= GETDATE()+30
GROUP BY LOCATION

Answer 1

This is an answer (all be it just a guess based on the limited question). I'm not a fan of placing CASE statements inside aggregates, but depending on environment, indexing, and data in the included tables, it might perform okay. Please be more involved when posting things. Show us what you've tried, explain the problem, give samples of data, include the desired output, all that fun stuff. The better the question, the better chance of a good answer. Okay, done on the high horse...
DECLARE #Forecast30days DATE
SET #Forecast30days = CURRENT_TIMESTAMP + 30
SELECT
wo.LOCATION
,COUNT(CASE WHEN wo.actfinish <= wo.targcompdate THEN wo.WONUM ELSE NULL END) AS OnTimePMWOs
,COUNT(CASE WHEN wo.actfinish >= wo.targcompdate THEN wo.WONUM ELSE NULL END) AS PastDuePMWOs
,COUNT(CASE WHEN pm.changedate IS NOT NULL THEN wo.WONUM ELSE NULL END) AS Forecast30days
FROM WORKORDER AS wo
LEFT JOIN PMFORECAST AS pm
ON wo.changedate = pm.changedate
AND pm.forecastdate >= #Forecast30days
WHERE wo.worktype = 'pm'
AND ((wo.actfinish IS NOT NULL AND wo.targcompdate IS NOT NULL)
OR (pm.changedate IS NOT NULL))
GROUP BY
wo.LOCATION