SQL Server 2008 R2: Combine two queries for optimization - sql-server

Question

I have the following query to optimize.
Following used to get the details from the profit table.
First inner SELECT: in the first select statement I have to get the details from the profit table and assign the row number for each row.
Second inner SELECT: in the second select statement I have to do some calculation (sum).
Outer SELECT: And get the result by combining them on id and also do some manipulation with data.
Code:
SELECT
a.p_id, p_Name,
convert(varchar, a.EndDate, 107) EndDate,
convert(varchar, a.EndDate, 106) NewEndDate,
LTRIM(a.p_id)) + '' + REPLACE(LEFT(CONVERT(VARCHAR, a.EndDate, 106), 6) + '' + RIGHT(CONVERT(VARCHAR, a.EndDate, 106), 2), ' ', '') as Compo,
a.GP,
b.fpro FirstProfit,
(b.fpro - b.spro) prodiff,
a.Qtity * a.GP as Ov,
a.Qtity,
b.fproChanPer
FROM
(SELECT
p_Name, p_id,
EndDate,
GP, FirstProfit,
prodiff,
Qtity,
ROW_NUMBER() OVER (PARTITION By p_Name, p_id ORDER BY EndDate) Rown
FROM
tbl_profit) a,
(SELECT
p_id,
CAST(SUM(FirstProfit) AS DECIMAL(24,2)) fpro,
CAST(SUM(SecondProfit) AS DECIMAL(24,2)) spro,
CAST(CAST(SUM(prodiff) AS DECIMAL(24,2)) / CAST(SUM(SecondProfit) AS DECIMAL(24,2)) * 100 AS DECIMAL(24,2)) fproChanPer
FROM
tbl_profit
GROUP BY
p_id) b
WHERE
b.p_id = a.p_id
AND Rown = 1
My question: can I combine those two (alias a and b) inner SELECT statements for query optimization?
My attempt: I have tried by using the following query but getting different calculation result.
SELECT p_Name,
p_id,
EndDate,
GP,
FirstProfit,
prodiff,
Qtity
ROW_NUMBER()OVER (PARTITION By p_Name,p_id ORDER By EndDate ) Rown,
CAST(SUM(FirstProfit) AS DECIMAL(24,2)) fpro,
CAST(SUM(SecondProfit) AS DECIMAL(24,2)) spro,
CAST(CAST(SUM(prodiff) AS DECIMAL(24,2)) /CAST(SUM(SecondProfit) AS DECIMAL(24,2)) * 100 AS DECIMAL(24,2)) fproChanPer
FROM tbl_profit
GROUP By p_id,p_Name,EndDate,GP,FirstProfit,prodiff,Qtity

Answer 1

tbl_profit must have multiple P_Name for a single p_id , when you are grouping by p_id only you are getting correct aggregate value whereas because of multiple p_name for a single p_id when you are grouping by p_id and p_name your aggregate sum values are getting double for wherever single p_id has more than one p_name.
The way you written query to get Rown = 1 records in this case is perfect, thought still have scope to optimize I have done few things please check.
SELECT
a.p_id,
p_Name,
CONVERT(varchar, a.EndDate, 107) EndDate,
CONVERT(varchar, a.EndDate, 106) NewEndDate,
LTRIM(a.p_id) + '' + REPLACE(LEFT(CONVERT(varchar, a.EndDate, 106), 6) + '' + RIGHT(CONVERT(varchar, a.EndDate, 106), 2), ' ', '') AS Compo,
a.GP,
b.fpro AS FirstProfit,
(b.fpro - b.spro) prodiff,
a.Qtity * a.GP AS Ov,
a.Qtity,
b.fproChanPer
FROM (
SELECT
a.p_Name,
a.p_id,
a.EndDate,
a.GP,
a.FirstProfit,
a.prodiff,
a.Qtity,
ROW_NUMBER() OVER (PARTITION BY a.p_Name, a.p_id ORDER BY a.EndDate) Rown
FROM tbl_profit AS a WITH (NOLOCK)
) AS a
INNER JOIN
(
SELECT
b.p_id,
CAST(SUM(b.FirstProfit) AS decimal(24, 2)) fpro,
CAST(SUM(b.SecondProfit) AS decimal(24, 2)) spro,
CAST(CAST(SUM(b.prodiff) AS decimal(24, 2)) / CAST(SUM(b.SecondProfit) AS decimal(24, 2)) * 100 AS decimal(24, 2)) fproChanPer
FROM tbl_profit AS b WITH (NOLOCK)
GROUP BY b.p_id
) AS b
ON b.p_id = a.p_id
AND a.Rown = 1