SQL选择最后一组日期？

Question

我的桌子看起来像这样:

Date    DataPoint      Type    Value
2000         HVAC    Phase1      220
2000         HVAC    Phase2      221
2000       SERVER    Phase1      222
2000       SERVER    Phase2      223
2001         HVAC    Phase1      220
2001         HVAC    Phase2      221
2001       SERVER    Phase1      222
2001       SERVER    Phase2      223
2002         HVAC    Phase1      220
2002         HVAC    Phase2      221
2002       SERVER    Phase1      222
2002       SERVER    Phase2      223
...
...
2013         HVAC    Phase1      220
2013         HVAC    Phase2      221
2013       SERVER    Phase1      222
2013       SERVER    Phase2      223

我想得到最后的日期,数据点,类型值的总和.

预期结果

Date    DataPoint        Value
2013         HVAC          441
2013       SERVER          445

我怎样才能做到这一点？提示,起点,代码示例？

谢谢...

Answer 1

使用TOP... WITH TIES简化:

SELECT TOP 1 WITH TIES Date, DataPoint, SUM(Value) AS Value
FROM YourTable
GROUP BY Date, DataPoint
ORDER BY Date DESC

SQL小提琴