sql 获取当天开始时间 结束时间

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))