sql中取得当前月的第一天

////当前月的第一天

select CONVERT(nvarchar(50),DateAdd(dd,-datePart(day,GetDate())+1,GETDATE()),23)

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

//////获得当前月的最后一天

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

select DATEDIFF(m,0,getdate())+1

2010-06-21 00:00:00.000

SELECT dateadd(ms,0,DATEADD(dd, DATEDIFF(dd,0,getdate()), 0))

2010-06-21 23:59:59.997

SELECT dateadd(ms,-3,DATEADD(dd, DATEDIFF(dd,-1,getdate()), 0))

ms步频是3

当月第一天

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

当月最后一天

SELECT   dateadd(ms,-3,DATEADD(mm,   DATEDIFF(m,0,getdate())+1,   0))