SQL日期操作语句

1.显示本月第一天
SELECT DATEADD(mm,DATEDIFF(mm,0,getdate()),0)
select convert(datetime,convert(varchar(8),getdate(),
120)+’01’,120)

2.显示本月最后一天
select dateadd(day,-1,convert(datetime,convert
(varchar(8),dateadd(month,1,getdate()),120)+’01’,120))
SELECT dateadd(ms,-3,DATEADD(mm,DATEDIFF(m,0,getdate())+1,0))

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

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

5.本年的第一天
SELECT DATEADD(yy,DATEDIFF(yy,0,getdate()),0)

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

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

8.本季度的第一天
SELECT DATEADD(qq,DATEDIFF(qq,0,getdate()),0)

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

10.查询本月的记录
select * from tableName where DATEPART(mm, theDate)
=DATEPART(mm, GETDATE()) and DATEPART(yy, theDate)
= DATEPART(yy, GETDATE())

11.查询本周的记录
select * from tableName where DATEPART(wk, theDate) = DATEPART
(wk, GETDATE()) and DATEPART(yy, theDate) = DATEPART(yy, GETDATE())

12.查询本季的记录 注：其中:GETDATE()是获得系统时间的函数。
select * from tableName where DATEPART(qq, theDate) = DATEPART
(qq, GETDATE()) and DATEPART(yy, theDate) = DATEPART(yy, GETDATE())

13.获取当月总天数:
select DATEDIFF(dd,getdate(),DATEADD
(mm, 1, getdate()))

select datediff(day,
dateadd(mm, datediff(mm,’’,getdate()), ’’),
dateadd(mm, datediff(mm,’’,getdate()), ’1900-02-01’))

14.获取当前为星期几
DATENAME(weekday, getdate())