SQL Server中获得本周，本月日期的方法

---上一周---

select DATEADD(wk,DATEDIFF(wk,0,getdate())-1,0)

select DATEADD(wk,DATEDIFF(wk,0,getdate())-1,6)

---本周---

select DATEADD(wk,DATEDIFF(wk,0,getdate()),0)

select DATEADD(wk,DATEDIFF(wk,0,getdate()),6)

---下一周 ---

select DATEADD(wk,DATEDIFF(wk,0,getdate())+1,0)

select DATEADD(wk,DATEDIFF(wk,0,getdate())+1,6)

---上一月第一天---

select DATEADD(mm,DATEDIFF(mm,0,getdate())-1,0)

---本月第一天---

select DATEADD(mm,DATEDIFF(mm,0,getdate()),0)

---下一月第一天---

select DATEADD(mm,DATEDIFF(mm,0,getdate())+1,0)

---本月方法一---

DECLARE @NOW DATETIME

DECLARE @FistDayOfCurrentMonth DATETIME

DECLARE @LastDayOfCurrentMonth DATETIME

SET @NOW = GETDATE()

SET @FistDayOfCurrentMonth = @NOW - DAY(@NOW) + 1

SET @LastDayOfCurrentMonth = DATEADD(MONTH, 1, @NOW - DAY(@NOW) + 1) - 1

SELECT @FistDayOfCurrentMonth

SELECT @LastDayOfCurrentMonth

---本月方法二---

DECLARE @FistDayOfCurrentMonth DATETIME

DECLARE @LastDayOfCurrentMonth DATETIME

SET @FistDayOfCurrentMonth = DATEADD(mm,DATEDIFF(mm,0,getdate()),0)

SET @LastDayOfCurrentMonth = DATEADD(MONTH, 1, @FistDayOfCurrentMonth) - 1

SELECT @FistDayOfCurrentMonth

SELECT @LastDayOfCurrentMonth

---上月---

DECLARE @FistDayOfLastMonth DATETIME

DECLARE @LastDayOfLastMonth DATETIME

SET @FistDayOfLastMonth = DATEADD(mm,DATEDIFF(mm,0,getdate())-1,0)

SET @LastDayOfLastMonth = DATEADD(MONTH, 1, @FistDayOfLastMonth) - 1

SELECT @FistDayOfLastMonth