T-SQL 将最近 6 周的数据检索到上周六

Question

SELECT TOP 100 *
FROM FactSalesDetail
WHERE TradingDate >= DATEADD(ww, -6, (Select MAX([TradingDate]) From FactSalesDetail))
ORDER BY TradingDate

任何人都可以建议我如何将上述 WHERE 子句从从我的事实 Table 中的最大日期检索最近 6 周的数据转换为最近 6 周到上周六的数据？

所以从今天开始就是 1 月 1 日星期六，然后从那之后 6 周？

Answer 1

使用当前工作日可以获得上周六。
如果您将@@DATEFIRST 带入等式，那么它就不会依赖于 DATEFIRST 设置。

SELECT TOP 100 *
FROM FactSalesDetail
WHERE TradingDate >= CONVERT(DATE, DATEADD(WEEK, -6, DATEADD(DAY, -(@@DATEFIRST+DATEPART(WEEKDAY,GETDATE()))%7, 
GETDATE())))
  AND TradingDate <= CONVERT(DATE, DATEADD(DAY, -(@@DATEFIRST+DATEPART(WEEKDAY,GETDATE()))%7, 
GETDATE()))
ORDER BY TradingDate

日期范围的测试代码段

SET DATEFIRST 7;

SELECT 
  datename(weekday, date_now) AS weekday_now, date_now
, datename(weekday, date1) AS wd1, date1
, datename(weekday, date2) AS wd2, date2 
FROM
(
    SELECT 
      CAST(GETDATE() AS DATE) AS date_now
    , CONVERT(DATE, DATEADD(WEEK, -6, DATEADD(DAY, -(@@DATEFIRST+DATEPART(WEEKDAY,GETDATE()))%7, 
GETDATE()))) AS date1
    , CONVERT(DATE, DATEADD(DAY, -(@@DATEFIRST+DATEPART(WEEKDAY,GETDATE()))%7, 
GETDATE())) AS date2
) q

weekday_now	date_now	wd1	date1	wd2	date2
Tuesday	2022-01-04	Saturday	2021-11-20	Saturday	2022-01-01

db<>fiddle here

T-SQL 将最近 6 周的数据检索到上周六

T-SQL Retrieve Last 6 Weeks Data to the Previous Saturday

tsql

date

where-clause