如何在SQL Server中选择过去七天的日期

Question

我想在select语句中选择最后七天的日期作为当前日期 2018-07-12

预期结果 :

Last_Seven_Days_Dates
2018-07-06
2018-07-07
2018-07-08
2018-07-09
2018-07-10
2018-07-11
2018-07-12

Answer 1

如果您在问题中列出的预期结果正是您正在寻找的,那么这将起到作用:

SELECT * FROM (
    SELECT CAST(GETDATE() AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -1, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -2, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -3, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -4, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -5, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -6, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -7, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
) AS the_table

结果:

Last_Seven_Days_Dates
---------------------
2018-07-05
2018-07-06
2018-07-07
2018-07-08
2018-07-09
2018-07-10
2018-07-11
2018-07-12

既然你说你想要这些在临时表中,我已经更新了答案,使其成为子查询,更容易加入或做一些事情.

此外,如果您需要在临时表中,您可以这样做:

SELECT * INTO #TempTableName FROM (
    SELECT CAST(GETDATE() AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -1, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -2, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -3, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -4, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -5, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -6, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
    UNION
    SELECT CAST(DATEADD(DAY, -7, GETDATE()) AS DATE) AS Last_Seven_Days_Dates
)

Answer 2

我使用以下内容生成日期系列

DECLARE @MinDate DATE = DATEADD(DAY, -7, GETDATE()),
        @MaxDate DATE = GETDATE();

SELECT  TOP (DATEDIFF(DAY, @MinDate, @MaxDate) + 1)
        Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, @MinDate)
FROM    sys.all_objects a;

如果需要使其可重用，可以将其包装在函数中并传入 MinDate 和 MaxDate