SQL语句中的日期计算
1. 本月的第一天
SELECT DATEADD(mm, DATEDIFF(mm,0,getdate()), 0)
2. 本月的最后一天
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(m,0,getdate())+1, 0))
3.上个月的第一天
select dateadd(m,-1, DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
4. 上个月的最后一天
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
5. 本周的星期一
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 0)
6.本周的周日
select dateadd(d,+6 ,DATEADD(wk, DATEDIFF(wk,0,getdate()), 0) )
7.上周的星期一
select dateadd(d,-7 ,DATEADD(wk, DATEDIFF(wk,0,getdate()), 0) )
8.上周的周日
select dateadd(d,-1 ,DATEADD(wk, DATEDIFF(wk,0,getdate()), 0) )
9. 一年的第一天
SELECT DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)
10. 季度的第一天
SELECT DATEADD(qq, DATEDIFF(qq,0,getdate()), 0)
11. 去年的最后一天
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate()), 0))
12. 本月的第一个星期一
select DATEADD(wk, DATEDIFF(wk,0,dateadd(dd,6-datepart(day,getdate)),getdate))),0)
13. 本年的最后一天
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0))。
Sql Server中的日期与时间函数
1. 当前系统日期、时间
select getdate()
2. dateadd 在向指定日期加上一段时间的基础上，返回新的 datetime 值
例如：向日期加上2天
select dateadd(day,2,'2004-10-15') --返回：2004-10-17 00:00:00.000
3. datediff 返回跨两个指定日期的日期和时间边界数。
select datediff(day,'2004-09-01','2004-09-18') --返回：17
4. datepart 返回代表指定日期的指定日期部分的整数。
SELECT DATEPART(month, '2004-10-15') --返回 10
5. datename 返回代表指定日期的指定日期部分的字符串
SELECT datename(weekday, '2004-10-15') --返回：星期五
6. day(), month(),year() --可以与datepart对照一下
select 当前日期=convert(varchar(10),getdate(),120)
,当前时间=convert(varchar(8),getdate(),114)
select datename(dw,'2004-10-15')
select 本年第多少周=datename(week,'2004-10-15')
,今天是周几=datename(weekday,'2004-10-15')
http://www.52186.cn/nibablog/blogview.asp?logID=333
sql日期格式转换
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来源：CSDN 发布会员：新书城收集整理 发布时间：2006-7-31 人气：384
在sql中，smalldatetime及datetime型的数据显示不是那么让人满意，因此我找了些格式化的方法列出来"
convert(char(10),datetime,101)
在数据库取出来的时候就转换好
select getdate()
2006-05-12 11:06:08.177
我整理了一下SQL Server里面可能经常会用到的日期格式转换方法:
举例如下:
select Convert(varchar(10),getdate(),120)
2006-05-12
select CONVERT(varchar, getdate(), 120 )
2006-05-12 11:06:08
select replace(replace(replace(CONVERT(varchar, getdate(), 120 ),'-',''),' ',''),':','')
20060512110608
select CONVERT(varchar(12) , getdate(), 111 )
2006/05/12
select CONVERT(varchar(12) , getdate(), 112 )
20060512
select CONVERT(varchar(12) , getdate(), 102 )
2006.05.12
其它几种不常用的日期格式转换方法:
select CONVERT(varchar(12) , getdate(), 101 )
0612/2005 select CONVERT(varchar(12) , getdate(), 103 )
12/09/2004
select CONVERT(varchar(12) , getdate(), 104 )
12.05.2006
select CONVERT(varchar(12) , getdate(), 105 )
12-05-2006
select CONVERT(varchar(12) , getdate(), 106 )
12 05 2006
select CONVERT(varchar(12) , getdate(), 107 )
05 12, 2006
select CONVERT(varchar(12) , getdate(), 108 )
11:06:08
select CONVERT(varchar(12) , getdate(), 109 )
0512 2006 1
select CONVERT(varchar(12) , getdate(), 110 )
09-12-2004
select CONVERT(varchar(12) , getdate(), 113 )
12 052006
select CONVERT(varchar(12) , getdate(), 114 )
11:06:08.177
============================================================================================
实例演练
select * from salesmb
select count(*) from salesdreport where employeeid='11'and productsid='7' and (updatetime between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --销售数量
select sum(sales) from salesmb where eid='11'and productsid='7' and (mbrq between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --目标数量
select dateadd(d,-day(getdate()),getdate())
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-'+cast(day(getdate()) as varchar)
select dateadd(m,1,dateadd(d,-day(getdate()),getdate()))
select dateadd(m,1,getdate())
=====================================================================================================================================================
select * from salesmb
select count(*) from salesdreport where employeeid='11'and productsid='7' and (updatetime between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --销售数量
select sum(sales) from salesmb where eid='11'and productsid='7' and (mbrq between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --目标数量
select dateadd(d,-day(getdate()),getdate())
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-'+cast(day(getdate()) as varchar)
select dateadd(m,1,dateadd(d,-day(getdate()),getdate()))
select dateadd(m,1,getdate())
======================================================================================================================================================
select * from salesmb
select count(*) from salesdreport where employeeid='11'and productsid='7' and (updatetime between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --销售数量
select sum(sales) from salesmb where eid='11'and productsid='7' and (mbrq between '2006-8-1 00:00:00'and '2006-8-30 00:00:00') --目标数量
select dateadd(d,-day(getdate()),getdate())
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-'+cast(day(getdate()) as varchar)
select dateadd(m,1,dateadd(d,-day(getdate()),getdate()))
select dateadd(m,1,getdate())
===============================================================================================================================
select getdate()
select dateadd(d,1,dateadd(d,-day(getdate()),getdate()))+"00:00"
declare @sdate smalldatetime
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'
select @sdate
select dateadd(day,-1,dateadd(Month,1,@sdate))
select cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'
select dateadd(d,-day(getdate()),getdate())
select dateadd(day,-1,dateadd(Month,1,cast(year(getdate()) as nvarchar)+'-'+cast(month(getdate()) as varchar)+'-1 00:00'))
select dateadd(d,-day(getdate()),getdate())
select dateadd(d,1,dateadd(d,-day(getdate()),getdate()))
select dateadd(m,
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
SELECT dateadd(ms,0,DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
