SQL hierarchy count totals report - sql

Question

I'm creating a report with SQL server 2012 and Report Builder which must show the total number of Risks at a high, medium and low level for each Parent Element.
Each Element contains a number of Risks which are rated at a certain level. I need the total for the Parent Elements. The total will include the number of all the Child Elements and also the number the Element itself may have.
I am using CTEs in my query- the code I have attached isn't working (there are no errors - it's just displaying the incorrect results) and I'm not sure that my logic is correct??
Hopefully someone can help. Thanks in advance.
My table structure is:
ElementTable
ElementTableId(PK) ElementName ElementParentId
RiskTable
RiskId(PK) RiskName RiskRating ElementId(FK)
My query:
WITH cte_Hierarchy(ElementId, ElementName, Generation, ParentElementId)
AS (SELECT ElementId,
NAME,
0,
ParentElementId
FROM Extract.Element AS FirtGeneration
WHERE ParentElementId IS NULL
UNION ALL
SELECT NextGeneration.ElementId,
NextGeneration.NAME,
Parent.Generation + 1,
Parent.ElementId
FROM Extract.Element AS NextGeneration
INNER JOIN cte_Hierarchy AS Parent
ON NextGeneration.ParentElementId = Parent.ElementId),
CTE_HighRisk
AS (SELECT r.ElementId,
Count(r.RiskId) AS HighRisk
FROM Extract.Risk r
WHERE r.RiskRating = 'High'
GROUP BY r.ElementId),
CTE_LowRisk
AS (SELECT r.ElementId,
Count(r.RiskId) AS LowRisk
FROM Extract.Risk r
WHERE r.RiskRating = 'Low'
GROUP BY r.ElementId),
CTE_MedRisk
AS (SELECT r.ElementId,
Count(r.RiskId) AS MedRisk
FROM Extract.Risk r
WHERE r.RiskRating = 'Medium'
GROUP BY r.ElementId)
SELECT rd.ElementId,
rd.ElementName,
rd.ParentElementId,
Generation,
HighRisk,
MedRisk,
LowRisk
FROM cte_Hierarchy rd
LEFT OUTER JOIN CTE_HighRisk h
ON rd.ElementId = h.ElementId
LEFT OUTER JOIN CTE_MedRisk m
ON rd.ElementId = m.ElementId
LEFT OUTER JOIN CTE_LowRisk l
ON rd.ElementId = l.ElementId
WHERE Generation = 1
Edit:
Sample Data
ElementTableId(PK) -- ElementName -- ElementParentId
1 ------------------- Main --------------0
2 --------------------Element1-----------1
3 --------------------Element2 ----------1
4 --------------------SubElement1 -------2
RiskId(PK) RiskName RiskRating ElementId(FK)
a -------- Financial -- High ----- 2
b -------- HR --------- High ----- 3
c -------- Marketing -- Low ------- 2
d -------- Safety -----Medium ----- 4
Sample Output:
Element Name High Medium Low
Main ---------- 2 ---- 1 -------1

Answer 1

Here is your sample tables
SELECT * INTO #TABLE1
FROM
(
SELECT 1 ElementTableId, 'Main' ElementName ,0 ElementParentId
UNION ALL
SELECT 2,'Element1',1
UNION ALL
SELECT 3, 'Element2',1
UNION ALL
SELECT 4, 'SubElement1',2
)TAB
SELECT * INTO #TABLE2
FROM
(
SELECT 'a' RiskId, 'Fincancial' RiskName,'High' RiskRating ,2 ElementId
UNION ALL
SELECT 'b','HR','High',3
UNION ALL
SELECT 'c', 'Marketing','Low',2
UNION ALL
SELECT 'd', 'Safety','Medium',4
)TAB
We are finding the children of a parent, its count of High,Medium and Low and use cross join to show parent with all the combinations of its children's High,Medium and Low
UPDATE
The below variable can be used to access the records dynamically.
DECLARE #ElementTableId INT;
--SET #ElementTableId = 1
And use the above variable inside the query
;WITH CTE1 AS
(
SELECT *,0 [LEVEL] FROM #TABLE1 WHERE ElementTableId = #ElementTableId
UNION ALL
SELECT E.*,e2.[LEVEL]+1 FROM #TABLE1 e
INNER JOIN CTE1 e2 on e.ElementParentId = e2.ElementTableId
AND E.ElementTableId<>#ElementTableId
)
,CTE2 AS
(
SELECT E1.*,E2.*,COUNT(RiskRating) OVER(PARTITION BY RiskRating) CNT
from CTE1 E1
LEFT JOIN #TABLE2 E2 ON E1.ElementTableId=E2.ElementId
)
,CTE3 AS
(
SELECT DISTINCT T1.ElementName,C2.RiskRating,C2.CNT
FROM #TABLE1 T1
CROSS JOIN CTE2 C2
WHERE T1.ElementTableId = #ElementTableId
)
SELECT *
FROM CTE3
PIVOT(MIN(CNT)
FOR RiskRating IN ([High], [Medium],[Low])) AS PVTTable
SQL FIDDLE
RESULT
UPDATE 2
I am updating as per your new requirement
Here is sample table in which I have added extra data to test
SELECT * INTO #ElementTable
FROM
(
SELECT 1 ElementTableId, 'Main' ElementName ,0 ElementParentId
UNION ALL
SELECT 2,'Element1',1
UNION ALL
SELECT 3, 'Element2',1
UNION ALL
SELECT 4, 'SubElement1',2
UNION ALL
SELECT 5, 'Main 2',0
UNION ALL
SELECT 6, 'Element21',5
UNION ALL
SELECT 7, 'SubElement21',6
UNION ALL
SELECT 8, 'SubElement22',7
UNION ALL
SELECT 9, 'SubElement23',7
)TAB
SELECT * INTO #RiskTable
FROM
(
SELECT 'a' RiskId, 'Fincancial' RiskName,'High' RiskRating ,2 ElementId
UNION ALL
SELECT 'b','HR','High',3
UNION ALL
SELECT 'c', 'Marketing','Low',2
UNION ALL
SELECT 'd', 'Safety','Medium',4
UNION ALL
SELECT 'e' , 'Fincancial' ,'High' ,5
UNION ALL
SELECT 'f','HR','High',6
UNION ALL
SELECT 'g','HR','High',6
UNION ALL
SELECT 'h', 'Marketing','Low',7
UNION ALL
SELECT 'i', 'Safety','Medium',8
UNION ALL
SELECT 'j', 'Safety','High',8
)TAB
I have written the logic in query
;WITH CTE1 AS
(
-- Here you will find the level of every elements in the table
SELECT *,0 [LEVEL]
FROM #ElementTable WHERE ElementParentId = 0
UNION ALL
SELECT ET.*,CTE1.[LEVEL]+1
FROM #ElementTable ET
INNER JOIN CTE1 on ET.ElementParentId = CTE1.ElementTableId
)
,CTE2 AS
(
-- Filters the level and find the major parant of each child
-- ie, 100->150->200, here the main parent of 200 is 100
SELECT *,CTE1.ElementTableId MajorParentID,CTE1.ElementName MajorParentName
FROM CTE1 WHERE [LEVEL]=1
UNION ALL
SELECT CTE1.*,CTE2.MajorParentID,CTE2.MajorParentName
FROM CTE1
INNER JOIN CTE2 on CTE1.ElementParentId = CTE2.ElementTableId
)
,CTE3 AS
(
-- Since each child have columns for main parent id and name,
-- you will get the count of each element corresponding to the level you have selected directly
SELECT DISTINCT CTE2.MajorParentName,RT.RiskRating ,
COUNT(RiskRating) OVER(PARTITION BY MajorParentID,RiskRating) CNT
FROM CTE2
JOIN #RiskTable RT ON CTE2.ElementTableId=RT.ElementId
)
SELECT MajorParentName, ISNULL([High],0)[High], ISNULL([Medium],0)[Medium],ISNULL([Low],0)[Low]
FROM CTE3
PIVOT(MIN(CNT)
FOR RiskRating IN ([High], [Medium],[Low])) AS PVTTable
SQL FIDDLE