日期想减的问题

Question

(2009-05-01）-（2008-06-01）=0.9年
2日期想减 最后相得到此结果..

Answer 1

SELECT DATEDIFF(YEAR,'2008-06-01','2009-05-01')

Answer 2

TimeSpan   tt=Convert.ToDateTime("2009-05-01")  -   Convert.ToDateTime("2008-06-01");   
  int   days=tt.TotalDays;//相差的天数

Answer 3

SELECT DATEDIFF(YEAR,'2008-06-01','2009-05-01')

Answer 4

declare @t1 datetime
declare @t2 datetime
set @t1='2009-05-01'
set @t2='2008-06-01'
select 1.0*(DATEDIFF(day, @t2, @t1))/(1.0*365)
                        
/*
                        
----------------------- 
.91506849（所影响的行数为 1 行）
*/

Answer 5

declare @t1 datetime
declare @t2 datetime
set @t1='2009-05-01'
set @t2='2008-06-01'
select cast (1.0*(DATEDIFF(day, @t2, @t1))/365 as numeric(7,1))
                        
/*
                        
----------------------- 
.91506849（所影响的行数为 1 行）
*/

Answer 6

SELECT cast(DATEDIFF(month,'2008-06-01','2009-04-01') as decimal)/12如果只保留一位小数
SELECT cast(cast(DATEDIFF(month,'2008-06-01','2009-04-01') as decimal)/12 as decimal(18,1))

Answer 7

SELECT CONVERT(NUMERIC(18,2),DATEDIFF(MM,'2008-06-01','2009-05-01'))*1.0/12

Answer 8

select datediff(mm,'2008-06-01','2009-05-01')/12.0

Answer 9

SELECT convert(decimal(18,1),DATEDIFF(day,'2007-01-01','2009-05-01')*0.1*10/365)

Answer 10

SELECT convert(decimal(18,1),DATEDIFF(day,'2008-06-01','2009-05-01')/365.0)
结果：0.9