SQL - 枢轴/ Unpivot？

Question

我在SQL Server 2008中的表格式如下（简化格式）：

Date Miles Cost

我想得到这样

  Previous Week  Current Week Variance 
Miles   

Cost

结果我怎样才能做到这一点？我是否需要pivot/unpivot或者什么是实现这个目标的最简单和最有效的方法。谢谢。

Answer 1

SELECT 'Miles' AS Type, SUM(CASE WHEN date = lastweek THEN miles ELSE 0 END) as lastweek 
, SUM(CASE WHEN date = thisweek THEN miles ELSE 0 END) as thisweek 
SUM(CASE WHEN date = lastweek THEN miles ELSE 0 END) - SUM(CASE WHEN date = thisweek THEN miles ELSE 0 END) as variance 
FROM yourtable 
UNION 
SELECT 'Cost' AS Type, SUM(CASE WHEN date = lastweek THEN cost ELSE 0 END) as lastweek 
, SUM(CASE WHEN date = thisweek THEN cost ELSE 0 END) as thisweek 
SUM(CASE WHEN date = lastweek THEN cost ELSE 0 END) - SUM(CASE WHEN date = thisweek THEN cost ELSE 0 END) as variance 
FROM yourtable 

这是不是100％正确，但语法应该是正确的，应该让你很接近好像你正在寻找