MySQL sum后再计算percentage的多种解决办法

		SELECT 
		b.*,
		ROUND(b.amount*100 / SUM(b.amount) OVER(),2) AS inv_salesShare
		FROM (	
				SELECT
					cm_cust_no,
					cm_co_name,
					SUM ( amount ) AS amount 
				FROM

 SELECT 
     P.PersonID, SUM(PA.Total)
     SUM(PA.Total) * 100 / [p] AS 'Percentage'
 FROM 
     Person P
 JOIN 
     Package PA ON P.PersonID = PA.PackageFK
 CROSS JOIN 
     (SELECT SUM(PA.[Total]) AS [p] 
      FROM Package PA) t
 GROUP BY 
     P.PersonID

SELECT PA.PersonID, SUM(PA.Total),
       SUM(PA.Total) * 100.0 / (SELECT SUM(PA.Total) FROM PA)
FROM Package PA
GROUP BY PA.PersonID;

;WITH PersonTotals AS
(
  SELECT P.PersonID, SUM(CAST(PA.Total AS MONEY)) Total
  FROM Person P
  JOIN Package PA ON P.PersonID = PA.PackageFK
  GROUP BY P.PersonID
),
GrandTotal AS
(
  SELECT SUM(PT.Total) Total
  FROM PersonTotals PT
)
SELECT PT.*, (PT.Total / NULLIF((SELECT Total From GrandTotal),0)) * 100 Percentage
FROM PersonTotals PT