Question

我想列出在表格中添加特定天数的学生。

@NumberOfDays INT = 15 -- When I list them the added subtraction result must match this result

SELECT S.Name, S.Surname, S.DateAdded
FROM STUDENT S
WHERE (SELECT CAST(GETDATE()-S.DateAdded) = @NumberOfDays)

但这不起作用。有人可以帮我吗？

Answer 1

带有增量的

DATEADD将扣除;

where S.DateAdded >= dateadd(day, -@NumberOfDays, getdate())

过去15天内添加的任何内容。

Answer 2

您应该使用DATEDIFF（Transact-SQL）函数，以下应该可以工作：

DECLARE @NumberOfDays INT = 15 -- When I list them the added subtraction result must match this result

SELECT S.Name, S.Surname, S.DateAdded
FROM STUDENT S
WHERE DATEDIFF(day, S.DateAdded, GETDATE()) = @NumberOfDays

有关此功能的更多信息：

http://msdn.microsoft.com/en-us/library/ms189794.aspx

Answer 3

您需要以这种方式使用DATEADD功能：

declare @numberofdays int
set @numberofdays = 15

SELECT S.Name, S.Surname, S.DateAdded
FROM STUDENT S
WHERE S.DateAdded >= dateadd(day, -@NumberOfDays, getdate())

以下是sqlfiddle。

Answer 4

这个怎么样。

您可以在sql中使用datediff函数来获取日期差异。

DECLARE @numberofdays as int
set @numberofdays = 15

SELECT S.Name, S.Surname, S.DateAdded
from STUDENT S
where datediff(dd,S.DateAdded,getdate())= @numberofdays;

Answer 5

SELECT S.Name, S.Surname, S.DateAdded 
FROM STUDENT S 
WHERE (SELECT months_between(GETDATE(), S.DateAdded) = @NumberOfDays)

减去两个日期

5 个答案: