SUM OVER PARTITION to calculate running total - tsql

Question

I am trying to modify my query to include a running total for each county in my report. Below is my working query with an attempt to use SUM OVER PARTITION commented out:
SELECT DATEPART(MONTH, r.received_date) AS [MonthID] ,
DATENAME(MONTH, r.received_date) AS [Month] ,
o.name AS [CountyName] ,
rsc.description AS [Filing] ,
COUNT(r.id) AS [Request_Total] ,
CAST (AVG(CAST (DATEDIFF(HOUR, received_date, completion_date) AS DECIMAL(8,2))) / 24 AS DECIMAL(8,2)) AS [Total_Time_Days]
--SUM(r.id) OVER (PARTITION BY o.name) AS [TotalFilings]
FROM dbo.requests AS [r]
INNER JOIN dbo.organizations AS [o] ON o.id = r.submitted_to_organiztion_id
INNER JOIN dbo.request_status_codes AS [rsc] ON rsc.code = r.request_status_code
WHERE r.submitted_to_organiztion_id < 68
AND r.request_type_code = 1
AND CAST(r.received_date AS DATE) >= '01/01/2016'
AND CAST(r.received_date AS DATE) <= '06/30/2016'
AND o.name = 'Alachua'
GROUP BY DATENAME(MONTH, r.received_date) ,
DATEPART(MONTH, r.received_date) ,
o.name ,
rsc.description
ORDER BY DATEPART(MONTH, r.received_date) ,
CountyName ,
Filing;
And the results look correct:
Perhaps I am misusing the SUM PARTITION BYbut my end goal is to add an additional column that will sum the filing types for each county by month.
For example, the additional column for the month of January should be 13,654 while February should be 14,238 and so on.
Could I get some advice on how to get this query working correctly? Thanks,

Answer 1

Not sure this is the best way or more efficient, but I was able to create a sub-query to obtain the results I wanted. I do believe a CTE or use of a Windows function would be better, but I haven't been able to get it to work. Here is my query however:
SELECT X.[MonthID] ,
X.[Month] ,
X.[CountyName] ,
X.[Filing] ,
X.[Avg_Time_Days] ,
SUM(X.Request_Total) AS [Total_Requests]
FROM ( SELECT DATEPART(MONTH, r.received_date) AS [MonthID] ,
DATENAME(MONTH, r.received_date) AS [Month] ,
o.name AS [CountyName] ,
rsc.description AS [Filing] ,
COUNT(r.id) AS [Request_Total] ,
CAST (AVG(CAST (DATEDIFF(HOUR, received_date,
completion_date) AS DECIMAL(8, 2)))
/ 24 AS DECIMAL(8, 2)) AS [Avg_Time_Days]
--, SUM(r.id) OVER (PARTITION BY o.name, rsc.description) AS [TotalFilings]
FROM dbo.requests AS [r]
INNER JOIN dbo.organizations AS [o] ON o.id = r.submitted_to_organiztion_id
INNER JOIN dbo.request_status_codes AS [rsc] ON rsc.code = r.request_status_code
WHERE r.submitted_to_organiztion_id < 68
AND r.request_type_code = 1
AND CAST(r.received_date AS DATE) >= '01/01/2016'
AND CAST(r.received_date AS DATE) <= '06/30/2016'
--AND o.name = 'Alachua'
GROUP BY DATENAME(MONTH, r.received_date) ,
DATEPART(MONTH, r.received_date) ,
o.name ,
rsc.description
--, r.id
--ORDER BY DATEPART(MONTH, r.received_date) ,
-- CountyName ,
-- Filing
) AS X
GROUP BY X.[MonthID] ,
X.[Month] ,
X.[CountyName] ,
X.[Filing] ,
X.[Avg_Time_Days]
ORDER BY X.[MonthID] ,
X.[Month] ,
X.[CountyName] ,
X.[Filing];