我有一个表,上面列出了人们的出生日期(目前是nvarchar(25))

我如何将其转换为日期,然后以年为单位计算他们的年龄?

我的数据如下所示

ID    Name   DOB
1     John   1992-01-09 00:00:00
2     Sally  1959-05-20 00:00:00

我希望看到:

ID    Name   AGE  DOB
1     John   17   1992-01-09 00:00:00
2     Sally  50   1959-05-20 00:00:00

当前回答

Ed Harper的解决方案是我发现的最简单的,当两个日期的月和日相隔1天或更少时,它永远不会返回错误的答案。我做了一个小小的修改来处理负年龄。

DECLARE @D1 AS DATETIME, @D2 AS DATETIME
SET @D2 = '2012-03-01 10:00:02'
SET @D1 = '2013-03-01 10:00:01'
SELECT
   DATEDIFF(YEAR, @D1,@D2)
   +
   CASE
      WHEN @D1<@D2 AND DATEADD(YEAR, DATEDIFF(YEAR,@D1, @D2), @D1) > @D2
      THEN - 1
      WHEN @D1>@D2 AND DATEADD(YEAR, DATEDIFF(YEAR,@D1, @D2), @D1) < @D2
      THEN 1
      ELSE 0
   END AS AGE

其他回答

你应按以下方法计算年数:-

select cast(datediff(DAY, '2000-03-01 10:00:01', '2013-03-01 10:00:00') / (365.23076923074) as int) as 'Age'

这很简单……

这将正确地处理生日和舍入的问题:

DECLARE @dob  datetime
SET @dob='1992-01-09 00:00:00'

SELECT DATEDIFF(YEAR, '0:0', getdate()-@dob)

所以上面的很多解决方案都是错误的DateDiff(yy,@Dob, @PassedDate)不会考虑两个日期的月和日。同样,只有在正确排序的情况下,省道部件才能进行比较。

下面的代码非常简单:

create function [dbo].[AgeAtDate](
    @DOB    datetime,
    @PassedDate datetime
)

returns int
with SCHEMABINDING
as
begin

declare @iMonthDayDob int
declare @iMonthDayPassedDate int


select @iMonthDayDob = CAST(datepart (mm,@DOB) * 100 + datepart  (dd,@DOB) AS int) 
select @iMonthDayPassedDate = CAST(datepart (mm,@PassedDate) * 100 + datepart  (dd,@PassedDate) AS int) 

return DateDiff(yy,@DOB, @PassedDate) 
- CASE WHEN @iMonthDayDob <= @iMonthDayPassedDate
  THEN 0 
  ELSE 1
  END

End
SELECT ID,
Name,
DATEDIFF(yy,CONVERT(DATETIME, DOB),GETDATE()) AS AGE,
DOB
FROM MyTable
select datediff(day,'1991-03-16',getdate()) \\for days,get date refers today date
select datediff(year,'1991-03-16',getdate()) \\for years
select datediff(month,'1991-03-16',getdate()) \\for month