常用的获取时间差的sql语句

本文章来自博客园：http://www.cnblogs.com/cyjch/archive/2012/02/06/2340216.html

为了以后方便使用，插个旗；

常用的获取时间差的sql语句

"select count(*) from [注册] where datediff(day,time,getdate())<1";//获取当天注册人员数
sql="select id,classid,classname,xiaoshoue,xiaoshou,jinhuo,kucun,addtime " 
sql=sql&" from xiaoshou where addtime between '" & format(starttime,"yyyy-mm-dd") & "' and '" & format(endtime,"yyyy-mm-dd") & "'" 
sql=sql&" order by id desc" 

Select Fylb,Pm,Gg,Dw,Dj,Sl,Je FROM cqyzypzx where zxdate between {^2003-7-1}and {^2003-8-1} 

近两个星期 
sql="select * from table where datediff(week,riqi,getdate())<=2" 

近三个月 
sql="select * from table where datediff(month,riqi,getdate())<=3" 

近一年 
sql="select * from table where datediff(year,riqi,getdate())<=1" 

Apply_Date between #"& startdate &" 23:59:59# and #"& enddate &" 23:59:59#"  

 

参考以下日期写法
---求相差天数
select datediff(day,'2004-01-01',getdate())


转贴:
--1.一个月第一天的
SELECT DATEADD(mm, DATEDIFF(mm,0,getdate()), 0)

--2.本周的星期一
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 0)

select dateadd(wk,datediff(wk,0,getdate()),6)
--3.一年的第一天
SELECT DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)

--4.季度的第一天
SELECT DATEADD(qq, DATEDIFF(qq,0,getdate()), 0)

--5.当天的半夜
SELECT DATEADD(dd, DATEDIFF(dd,0,getdate()), 0)

--6.上个月的最后一天
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))

--7.去年的最后一天
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate()), 0))

--8.本月的最后一天
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(m,0,getdate())+1, 0))

--9.本年的最后一天
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0))

--10.本月的第一个星期一
select DATEADD(wk,
DATEDIFF(wk,0,dateadd(dd,6-datepart(day,getdate()),getdate())), 0)


 

--查询本周注册人数
select count(*) from [user]
where datediff(week,create_day-1,getdate())=0

--上周注册人数
select count(*) from [user]
where datediff(week,create_day-1,getdate())=1


--本月注册人数
select count(*) from [user]
where datediff(month,create_day,getdate())=0

--上月注册人数
select count(*) from [user]
where datediff(month,create_day,getdate())=1

 

 

--如果要效率,这样写查询

--查询本周注册人数
select count(*) from [user]
where create_day>=dateadd(day,2-datepart(weekday,getdate()),convert(varchar,getdate(),112))
 and create_day<dateadd(day,9-datepart(weekday,getdate()),convert(varchar,getdate(),112))

--上周注册人数
select count(*) from [user]
where create_day>=dateadd(day,-5-datepart(weekday,getdate()),convert(varchar,getdate(),112))
 and create_day<dateadd(day,2-datepart(weekday,getdate()),convert(varchar,getdate(),112))


--本月注册人数
select count(*) from [user]
where create_day>=dateadd(day,1-day(getdate()),convert(varchar,getdate(),112))
 and create_day<dateadd(month,1,dateadd(day,1-day(getdate()),convert(varchar,getdate(),112)))

--上月注册人数
select count(*) from [user]
where create_day>=dateadd(month,-1,dateadd(day,1-day(getdate()),convert(varchar,getdate(),112)))
 and create_day<dateadd(day,1-day(getdate()),convert(varchar,getdate(),112))