Question

我已经编写了SQL来选择过去三个月的用户数据，但我认为目前它每天更新。

我想改变它，以便现在十月它不计算Octobers数据，而是七月到九月数据，并在我们搬到十一月时改为八月到十月

这是我目前获得的SQL：

declare @Today datetime
declare @Category varchar(40)
set @Today = dbo.udf_DateOnly(GETDATE())

set @Category = 'Doctors active last three months updated'          
declare @last3monthsnew datetime 
set @last3monthsnew=dateadd(m,-3,dbo.udf_DateOnly(GETDATE()))          
delete from LiveStatus_tbl where Category = @Category          


  select @Category, count(distinct U.userid)         
  from   UserValidUKDoctor_vw U        
  WHERE  LastLoggedIn >= @last3monthsnew

我如何编辑它来做到这一点？

Answer 1

WHERE  LastLoggedIn >= DATEADD(month, DATEDIFF(month, 0, GETDATE())-3, 0)
 AND   LastLoggedIn <  DATEADD(month, DATEDIFF(month, 0, GETDATE()), 0)

上述声明将在7月至本月初之前返回任何结果。

Answer 2

参考此答案以获取该月的第一天：

<强> How can I select the first day of a month in SQL?

您可以检测月份限制，如下所示：

select DATEADD(month, DATEDIFF(month, 0, getdate()) - 3, 0) AS StartOfMonth
select DATEADD(month, DATEDIFF(month, 0, getdate()), 0) AS EndMonth

然后您可以将其添加到变量中或直接添加到WHERE子句中：

declare @StartDate datetime
declare @EndDate datetime

set @StartDate = DATEADD(month, DATEDIFF(month, 0, getdate()) - 3, 0) 
set @EndDate = DATEADD(month, DATEDIFF(month, 0, getdate()), 0) 

select @Category, count(distinct U.userid)         
from   UserValidUKDoctor_vw U        
where LastLoggedIn >= @StartDate AND LastLoggedIn < @EndDate

或者：

select @Category, count(distinct U.userid)         
from   UserValidUKDoctor_vw U        
where LastLoggedIn >= DATEADD(month, DATEDIFF(month, 0, getdate()) - 3, 0) 
  and LastLoggedIn < DATEADD(month, DATEDIFF(month, 0, getdate()), 0)

Answer 3

如何使用BETWEEN？

WHERE LastLoggedIn 
BETWEEN
DATEADD(month, DATEDIFF(month, 0, GETDATE())-3, 0) 
AND 
DATEADD(month, DATEDIFF(month, 0, GETDATE()), 0)

SQL最近三个月

3 个答案: