Find Top Most AND Lowest In a Table's Group Column - sql

Question

I have a table and there are 4 fields in it, ID, Price, QTY, Ratting and Optional [Position].
I have all the records Grouped By Columns [Qty,Ratting]
I have to define the position of groupwise and store that Position into Optional column.
For better understanding I have added an image with data in table:
On the basis of QTY in Each Rating I have to Mark Top3, Bottom3 and Rest of them as remaining.
I am not getting how to do it.
Can anybody suggest me how to do it?
So far what I've tried is:
Declare #RankTable TABLE
(
ID INT,
Price Decimal (10,2),
Qty INT,
Ratting INT
)
INSERT INTO #RankTable
SELECT 1,10,15,1
UNION ALL
SELECT 2,11,11,1
UNION ALL
SELECT 3,96,10,1
UNION ALL
SELECT 4,96,8,1
UNION ALL
SELECT 5,56,7,1
UNION ALL
SELECT 6,74,5,1
UNION ALL
SELECT 7,93,4,1
UNION ALL
SELECT 8,98,2,1
UNION ALL
SELECT 9,12,1,1
UNION ALL
SELECT 10,32,80,2
UNION ALL
SELECT 11,74,68,2
UNION ALL
SELECT 12,58,57,2
UNION ALL
SELECT 13,37,43,2
UNION ALL
SELECT 14,79,32,2
UNION ALL
SELECT 15,29,28,2
UNION ALL
SELECT 16,46,17,2
UNION ALL
SELECT 17,86,13,2
UNION ALL
SELECT 19,75,110,3
UNION ALL
SELECT 20,27,108,3
UNION ALL
SELECT 21,38,104,3
UNION ALL
SELECT 22,87,100,3
UNION ALL
SELECT 23,47,89,3
DECLARE #PositionGroup VARCHAR(1)
SELECT *,ISNULL(#PositionGroup,'') AS Position FROM #RankTable

Answer 1

You can try this:
SELECT ID
,Price
,Qty
,Ratting
,CASE WHEN RowID >= 1 AND RowID <= 3
THEN 0
ELSE CASE WHEN RowID > Total - 3 THEN 1 ELSE 2 END END AS Position
FROM (SELECT ID
,Price
,Qty
,Ratting
,COUNT(*) OVER(PARTITION BY Ratting) AS Total
,ROW_NUMBER() OVER(PARTITION BY Ratting ORDER BY Qty DESC) AS RowID
,ISNULL(#PositionGroup,'') AS Position
FROM #RankTable) AS T

Answer 2

Use Window Function. Try this.
;WITH cte
AS (SELECT *,
Row_number()OVER(partition BY rating ORDER BY id) rn,
count(id)OVER(partition BY rating) mx
FROM #RankTable)
SELECT ID,
Price,
Qty,
Rating,
mx - rn,
CASE WHEN rn IN ( 1, 2, 3 ) THEN 0
WHEN mx - rn IN( 0, 1, 2 ) THEN 1
ELSE 2
END position
FROM cte

Answer 3

try this as well.
;WITH cte AS
(
SELECT MAX(Row) [Max],
MIN(Row) [Min],
LU.Ratting
FROM (
SELECT *,
ROW_NUMBER() OVER(PARTITION BY Ratting ORDER BY Qty DESC) Row
FROM #RankTable)LU
GROUP BY LU.Ratting
)
SELECT ID,
R.Price,
R.Qty,
cte.Ratting,
CASE WHEN (Row - Min) <= 2 THEN 0 WHEN (Max - Row) <= 2 THEN 1 ELSE 2 END Position
FROM cte
JOIN (
SELECT Ratting,
ID,
Price,
Qty,
ROW_NUMBER() OVER(PARTITION BY Ratting ORDER BY Qty DESC) [Row]
FROM #RankTable
) R ON R.Ratting = cte.Ratting
Result: