SQL 查询帮助获取每月值

Question

我有一个查询，它基本上根据几个条件对当前月份的一列求和。我想获得每个月的价值，但似乎无法理解它。

DECLARE @d1 DATETIME = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()),0);
DECLARE @d2 DATETIME = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0);

SELECT    sum(SUMCOL)   as Total 
FROM COVERAGE
where

(COVERAGE_START_DATE>=@d1 and COVERAGE_START_DATE< @d2 and not PROCESSED_DATE>=@d2)   or

(COVERAGE_START_DATE< @d1 and PROCESSED_DATE>=@d1 and PROCESSED_DATE<@d2)

我只是想得到月份

SELECT MONTH(PROCESSED_DATE)MONTH, sum(SUMCOL) as Total 

然后按月分组…………

GROUP BY  MONTH(COVERAGE_START_DATE)

但后来意识到这不会，因为我也需要处理 PROCESSED_DATE 列并且也无法获取额外的逻辑。

无论如何，我希望能得到一些帮助。显然 SQL 查询不是我的事 :) 必须有一种更有效（和正确）的方法，但我似乎无法理解它。

Answer 1

使用HAVING 子句。

SELECT MONTH(PROCESSD_DATE) AS MONTH, SUM(SUMCOL) AS Total
FROM COVERAGE
GROUP BY MONTH(PROCESSD_DATE)
HAVING ((COVERAGE_START_DATE BETWEEN @d1 AND @d2) AND PROCESSED_DATE <= @d2)
OR (COVERAGE_START_DATE < @d1 AND (PROCESSED_DATE BETWEEN @d1 AND @d2))