SQL - 從dateTime列中獲取基於月的數據

Question

使用SQL Server，我有一個包含啓動日期（dateTime）的列。我想報告上個月（從觀看日期）到本月和下個月的所有內容。

所以基本上是整整3個月的時間。

寫這個的最好方法是什麼？

Answer 1

您正在尋找這樣的事情？

DECLARE 
    @StartDate DATETIME, 
    @EndDate DATETIME 

SELECT 
    @StartDate = DATEADD(MM, DATEDIFF(MM, 0, GETDATE()) - 1, 0), 
    @EndDate = DATEADD(MM, DATEDIFF(MM, 0, GETDATE()) + 2, 0) 

-- DATEADD(MM, DATEDIFF(MM, 0, GETDATE()), 0), -- beginning of this month 
-- DATEADD(MM, DATEDIFF(MM, 0, GETDATE()) - 1, 0), -- beginning of last month 
-- DATEADD(MM, DATEDIFF(MM, 0, GETDATE()) + 1, 0) -- beginning of next month 
-- DATEADD(MM, DATEDIFF(MM, 0, GETDATE()) + 2, 0) -- beginning of two months from now 

SELECT 
    * 
FROM 
    [Table] 
WHERE 
    [LaunchDate] >= @StartDate 
AND [LaunchDate] < @EndDate 

這會給你所有從上月的開始，兩個月從現在（整整3個月的範圍）開始之前開始結果

Answer 2

SELECT Foo 
FROM Bar 
WHERE LaunchDate >= DATEADD(mm, -1, GETDATE()) 
AND LaunchDate <= DATEADD(mm, 1, GETDATE()) 

Answer 3

也許像SELECT /*what_you_want*/ from launches WHERE lauchDate BETWEEN DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) - 1, '19000101') AND DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) + 2, '19000101')