取出某个月有几天

 取出某个月有几天

--取出这个月有几天
SELECT 32-DAY(GETDATE()+(32-DAY(GETDATE())))

--取出上个月有几天
select day(getdate()-day(getdate()))

--取出某个月有几天
SELECT 32-DAY(CAST('2000-02-22' AS DATETIME)+(32-DAY(CAST('2000-02-22' AS DATETIME))))

取月初月末和月份间隔

--1.取月初月末
declare @startdate datetime
select @startdate=dateadd(dd,-datepart(dd,getdate())+1,getdate())
select SUBSTRING(Convert(varchar(100),@startdate ,23),1,10)
declare @enddate datetime
select @enddate=dateadd(dd,-datepart(dd,getdate()),dateadd(mm,1,getdate()))
select SUBSTRING(Convert(varchar(100),@enddate ,23),1,10)
 

--2.取间隔一个月
declare @startdate datetime
select @startdate= dateadd(MM,-1,dateadd(dd,-datepart(dd,getdate())+1,getdate()))

select SUBSTRING(Convert(varchar(100),@startdate ,23),1,10)
declare @enddate datetime
select @enddate=dateadd(MM,-1,dateadd(dd,-datepart(dd,getdate())+1,dateadd(mm,1,getdate())))
select SUBSTRING(Convert(varchar(100),@enddate ,23),1,10)