SUM of only TOP 10 rows

问题

I have a query where I am only selecting the TOP 10 rows, but I have a SUM function in there that is still taking the sum of all the rows (disregarding the TOP 10). How do I get the total of only the top 10 rows? Here is my SUM function :

SUM( fact.Purchase_Total_Amount) Total

回答1:

Have you tried to use something like this:

SELECT SUM(Whatever)
FROM (
    SELECT TOP(10) Whatever
    FROM TableName
) AS T

回答2:

Use the TOP feature with a nested query

SELECT SUM(innerTable.Purchase_Total_Amount) FROM
(SELECT TOP 10 Purchase_Total_Amount FROM Table) as innerTable

来源：https://stackoverflow.com/questions/28479926/sum-of-only-top-10-rows