你如何在 SQL 中找到去年相同的工作日?

问题描述

通常在销售报告等中，您需要将这一天与去年的同一天进行比较，但要基于相同的工作日"，而不是每月的某天".

Often in sales reports and so on you need to compare this day to the same day last year, but based on the same "weekday", not "day of month".

例如，今天是 2013 年 6 月 20 日和星期四.我想查看今天的销售额与去年同一个星期四的销售额(2012 年 6 月 21 日，而 2012 年 6 月 20 日是星期三).

So for example, today is the 20th June 2013 and a Thursday. I want to see sales for today, versus the same THURSDAY last year (21st June 2012, as opposed to 20th June 2012 which was a Wednesday).

如何在 T-SQL 中做到这一点?

How can this be done in T-SQL?

推荐答案

DECLARE @now Date
SET @now = '2013-06-20' -- your example
SELECT DATEADD(week, -52, @now)

SET @now = '2012-06-21' -- leap year test
SELECT DATEADD(week, -52, @now)