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
CREATE function dbo.AgeAtDate(
@DOB datetime,
@CompareDate datetime
)
returns INT
as
begin
return CASE WHEN @DOB is null
THEN
null
ELSE
DateDiff(yy,@DOB, @CompareDate)
- CASE WHEN datepart(mm,@CompareDate) > datepart(mm,@DOB) OR (datepart(mm,@CompareDate) = datepart(mm,@DOB) AND datepart(dd,@CompareDate) >= datepart(dd,@DOB))
THEN 0
ELSE 1
END
END
End
GO
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