TSQL - 比较格式化为字符串的日期(年和日历周)

问题描述

我需要一种方法来比较以下字符串格式的日期:'2015 CW 14' 或 '2016 CW 03''使用当前年和周，以测试该值是否在过去或>=当前年和周.

I need a way to compare dates in the following string format: '2015 CW 14' or '2016 CW 03'' with the current year and week in order to test if the value is in the past or >= the current year and week.

DECLARE @cw VARCHAR(50) 

SET @cw = '2015 CW 13' 

SELECT @cw; 

SELECT Cast(Year(Getdate()) AS VARCHAR(50)) 
       + ' CW ' 
       + Cast(Datepart(week, Getdate()) AS VARCHAR(50)) 

我相信我的方法不会让我达到目标.

I believe my approach won't get me there.

推荐答案

我认为你在 2016 CW 03 上有问题我将你的声明编辑为 @cw2，并且您可以看到 < 或 > 或 = 将用于比较.

I think you have a problem on 2016 CW 03 I edit your statement to @cw2, And you can see < or > or = will work for comparing.

这条线索很有用:

DECLARE @cw  VARCHAR(50), 
        @cw2 VARCHAR(50) 

SET @cw = '2015 CW 03' 
SET @cw2 = Cast(Year(Getdate()) AS VARCHAR(50)) 
           + ' CW ' 
           + RIGHT('00' + Cast(Datepart(week, Getdate()) AS VARCHAR(50)), 2) 

SELECT @cw, 
       @cw2, 
       CASE 
         WHEN @cw = @cw2 THEN 0 
         WHEN @cw < @cw2 THEN -1 
         ELSE 1 
       END