Grouping Hierarchical data (parentID+ID) and running sum? - sql

Question

I have the following data:
ID parentID Text Price
1 Root
2 1 Flowers
3 1 Electro
4 2 Rose 10
5 2 Violet 5
6 4 Red Rose 12
7 3 Television 100
8 3 Radio 70
9 8 Webradio 90
I am trying to group this data with Reporting Services 2008 and have a sum of the price per group of level 1 (Flowers/Electro) and for level 0 (Root).
I have a table grouped on [ID] with a recursive parent of [parendID] and I am able to calculate the sum for the level 0 (just one more row in the table outside the group), but somehow I am not able to create sum's per group as SRSS does "create" groups per level. My desired result looks like so:
ID Text Price
1 Root
|2 Flowers
|-4 Rose 10
|-5 Violet 5
| |-6 Red Rose 12
| Group Sum-->27
|3 Electro
|-7 Television 100
|-8 Radio 70
|-9 Webradio 90
Group Sum-->260
----------------------
Total 287
(indentation of ID just added for level clarification)
With my current approach I cannot get the group sums, so I figured out I would need the following data structure:
ID parentID Text Price level0 level1 level2 level3
1 Root 1
2 1 Flowers 1 1
3 1 Electro 1 2
4 2 Rose 10 1 1 1
5 2 Violet 5 1 1 2
6 4 Red Rose 12 1 1 1 1
7 3 Television 100 1 2 1
8 3 Radio 70 1 2 2
9 8 Webradio 90 1 2 2 1
When having the above structure I can create an outer grouping of level0, with child groupings level1, level2, level3 accordingly . When now having a "group sum" on level1, and the total sum outside the group I have EXACTLY what I want.
My question is the following:
How do I either achieve my desired result with my current data structure, or how do I convert my current data structure (outer left joins?) into the "new data structure" temporarily - so I can run my report off of the temp table?
Thanks for taking your time,
Dennis

Answer 1

WITH q AS
(
SELECT id, parentId, price
FROM mytable
UNION ALL
SELECT p.id, p.parentID, q.price
FROM q
JOIN mytable p
ON p.id = q.parentID
)
SELECT id, SUM(price)
FROM q
GROUP BY
id
Update:
A test script to check:
DECLARE #table TABLE (id INT NOT NULL PRIMARY KEY, parentID INT, txt VARCHAR(200) NOT NULL, price MONEY)
INSERT
INTO #table
SELECT 1, NULL, 'Root', NULL
UNION ALL
SELECT 2, 1, 'Flowers', NULL
UNION ALL
SELECT 3, 1, 'Electro', NULL
UNION ALL
SELECT 4, 2, 'Rose', 10
UNION ALL
SELECT 5, 2, 'Violet', 5
UNION ALL
SELECT 6, 4, 'Red Rose', 12
UNION ALL
SELECT 7, 3, 'Television', 100
UNION ALL
SELECT 8, 3, 'Radio', 70
UNION ALL
SELECT 9, 8, 'Webradio', 90;
WITH q AS
(
SELECT id, parentId, price
FROM #table
UNION ALL
SELECT p.id, p.parentID, q.price
FROM q
JOIN #table p
ON p.id = q.parentID
)
SELECT t.*, psum
FROM (
SELECT id, SUM(price) AS psum
FROM q
GROUP BY
id
) qo
JOIN #table t
ON t.id = qo.id
Here's the result:
1 NULL Root NULL 287,00
2 1 Flowers NULL 27,00
3 1 Electro NULL 260,00
4 2 Rose 10,00 22,00
5 2 Violet 5,00 5,00
6 4 Red Rose 12,00 12,00
7 3 Television 100,00 100,00
8 3 Radio 70,00 160,00
9 8 Webradio 90,00 90,00

Answer 2

I found a really ugly way to do what I want - maybe there is something better?
SELECT A.Text, A.Price,
CASE
WHEN D.Text IS NULL
THEN
CASE
WHEN C.Text IS NULL
THEN
CASE
WHEN B.Text IS NULL
THEN
A.ID
ELSE B.ID
END
ELSE C.ID
END
ELSE D.ID
END
AS LEV0,
CASE
WHEN D.Text IS NULL
THEN
CASE
WHEN C.Text IS NULL
THEN
CASE
WHEN B.Text IS NULL
THEN
NULL
ELSE A.ID
END
ELSE B.ID
END
ELSE C.ID
END
AS LEV1,
CASE
WHEN D.Text IS NULL
THEN
CASE
WHEN C.Text IS NULL
THEN
NULL
ELSE A.ID
END
ELSE B.ID
END
AS LEV2,
CASE
WHEN D.Text IS NULL
THEN NULL
ELSE A.ID
END
AS LEV3
FROM dbo.testOld AS A LEFT OUTER JOIN
dbo.testOld AS B ON A.parentID = B.ID LEFT OUTER JOIN
dbo.testOld AS C ON B.parentID = C.ID LEFT OUTER JOIN
dbo.testOld AS D ON C.parentID = D.ID
Output of this is:
Text Price LEV0 LEV1 LEV2 LEV3
---------- ----------- ----------- ----------- ----------- -----------
Root NULL 1 NULL NULL NULL
Flowers NULL 1 3 NULL NULL
Electro NULL 1 4 NULL NULL
Television 100 1 4 5 NULL
Radio 70 1 4 6 NULL
Rose 10 1 3 7 NULL
Violet 5 1 3 8 NULL
Webradio 90 1 4 5 14
Red Rose 12 1 3 7 15
With this structure I can go ahead and create 4 nested groups on the LEV0-3 columns including subtotals per group (as shown above in my desired result).