使用汇总来计算总计，同时显示月份名称并按月份编号排序

Question

此内容改编自https://www.databasejournal.com/features/mssql/using-the-rollup-cube-and-grouping-sets-operators.html

这就是我所拥有的：

SELECT DATENAME(month, PurchaseDate) PurchaseMonth
     , CASE WHEN DATENAME(month, PurchaseDate) is null then 'Grand Total' 
                   ELSE coalesce (PurchaseType,'Monthly Total') end AS PurchaseType
     , Sum(PurchaseAmt) as SummorizedPurchaseAmt
FROM tPurchaseItem
GROUP BY   ROLLUP(DATENAME(month, PurchaseDate), PurchaseType);

这有效，但未按时间顺序排序。

结果是这样的：

我希望订单为一月，二月等。

Answer 1

DATENAME返回一个nvarchar，因此顺序将类似于nvarchar。 'April' < 'January'。

一种方法是将您的GROUP BY更改为DATEPART并从数字中得出月份的名称：

SELECT CHOOSE(DATEPART(MONTH, PurchaseDate),'January','February','March','April','May','June','July','August','September','October','November','December') AS PurchaseMonth
     , CASE WHEN DATENAME(month, PurchaseDate) is null then 'Grand Total' 
                   ELSE coalesce (PurchaseType,'Monthly Total') end AS PurchaseType
     , Sum(PurchaseAmt) as SummorizedPurchaseAmt
FROM tPurchaseItem
GROUP BY   ROLLUP(DATEPART(MONTH, PurchaseDate), PurchaseType);