在SQL中执行百分比计算

Question

我尝试按组计算总和并计算每个组占多少％。这是很容易使用GROUP BY做SUMIF但后来我被困在SUM (ALL) - 我想我可以尝试做SUM(CASE IF GROUP='A' THEN END) + SUM(CASE IF GROUP='B'...但随后WHATIF有更多GROUP :(

SELECT GROUP, SUM(SALES), SUM(SALES)/TOTAL FROM DATABASE.SALETABLE

Answer 1

您可以使用SUM ... OVER()以获得总销售额。

SELECT [Group], 
     SUM(SALES) AS [Sales], 
     100.0 * SUM(SALES)/SUM(SUM(SALES)) OVER() AS [%] 
FROM YourTable 
GROUP BY [Group] 

SQL Fiddle