I have a table listing people along with their date of birth (currently a nvarchar(25))
How can I convert that to a date, and then calculate their age in years?
My data looks as follows
ID Name DOB
1 John 1992-01-09 00:00:00
2 Sally 1959-05-20 00:00:00
I would like to see:
ID Name AGE DOB
1 John 17 1992-01-09 00:00:00
2 Sally 50 1959-05-20 00:00:00
This question is related to
sql-server
sql-server-2005
select
date
I have used this query in our production code for nearly 10 years:
SELECT FLOOR((CAST (GetDate() AS INTEGER) - CAST(Date_of_birth AS INTEGER)) / 365.25) AS Age
So many of the above solutions are wrong DateDiff(yy,@Dob, @PassedDate) will not consider the month and day of both dates. Also taking the dart parts and comparing only works if they're properly ordered.
THE FOLLOWING CODE WORKS AND IS VERY SIMPLE:
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
The answer marked as correct is nearer to accuracy but, it fails in following scenario - where Year of birth is Leap year and day are after February month
declare @ReportStartDate datetime = CONVERT(datetime, '1/1/2014'),
@DateofBirth datetime = CONVERT(datetime, '2/29/1948')
FLOOR(DATEDIFF(HOUR,@DateofBirth,@ReportStartDate )/8766)
OR
FLOOR(DATEDIFF(HOUR,@DateofBirth,@ReportStartDate )/8765.82) -- Divisor is more accurate than 8766
-- Following solution is giving me more accurate results.
FLOOR(DATEDIFF(YEAR,@DateofBirth,@ReportStartDate) - (CASE WHEN DATEADD(YY,DATEDIFF(YEAR,@DateofBirth,@ReportStartDate),@DateofBirth) > @ReportStartDate THEN 1 ELSE 0 END ))
It worked in almost all scenarios, considering leap year, date as 29 feb, etc.
Please correct me if this formula have any loophole.
Since there isn't one simple answer that always gives the correct age, here's what I came up with.
SELECT DATEDIFF(YY, DateOfBirth, GETDATE()) -
CASE WHEN RIGHT(CONVERT(VARCHAR(6), GETDATE(), 12), 4) >=
RIGHT(CONVERT(VARCHAR(6), DateOfBirth, 12), 4)
THEN 0 ELSE 1 END AS AGE
This gets the year difference between the birth date and the current date. Then it subtracts a year if the birthdate hasn't passed yet.
Accurate all the time - regardless of leap years or how close to the birthdate.
Best of all - no function.
EDIT: THIS ANSWER IS INCORRECT. I leave it in here as a warning to anyone tempted to use dayofyear, with a further edit at the end.
If, like me, you do not want to divide by fractional days or risk rounding/leap year errors, I applaud @Bacon Bits comment in a post above https://stackoverflow.com/a/1572257/489865 where he says:
If we're talking about human ages, you should calculate it the way humans calculate age. It has nothing to do with how fast the earth moves and everything to do with the calendar. Every time the same month and day elapses as the date of birth, you increment age by 1. This means the following is the most accurate because it mirrors what humans mean when they say "age".
He then offers:
DATEDIFF(yy, @date, GETDATE()) -
CASE WHEN (MONTH(@date) > MONTH(GETDATE())) OR (MONTH(@date) = MONTH(GETDATE()) AND DAY(@date) > DAY(GETDATE()))
THEN 1 ELSE 0 END
There are several suggestions here involving comparing the month & day (and some get it wrong, failing to allow for the OR as correctly here!). But nobody has offered dayofyear, which seems so simple and much shorter. I offer:
DATEDIFF(year, @date, GETDATE()) -
CASE WHEN DATEPART(dayofyear, @date) > DATEPART(dayofyear, GETDATE()) THEN 1 ELSE 0 END
[Note: Nowhere in SQL BOL/MSDN is what DATEPART(dayofyear, ...) returns actually documented! I understand it to be a number in the range 1--366; most importantly, it does not change by locale as per DATEPART(weekday, ...) & SET DATEFIRST.]
EDIT: Why dayofyear goes wrong: As user @AeroX has commented, if the birth/start date is after February in a non leap year, the age is incremented one day early when the current/end date is a leap year, e.g. '2015-05-26', '2016-05-25' gives an age of 1 when it should still be 0. Comparing the dayofyear in different years is clearly dangerous. So using MONTH() and DAY() is necessary after all.
you should count years by following way :-
select cast(datediff(DAY, '2000-03-01 10:00:01', '2013-03-01 10:00:00') / (365.23076923074) as int) as 'Age'
it's very easy...
We used something like here, but then taking the average age:
ROUND(avg(CONVERT(int,DATEDIFF(hour,DOB,GETDATE())/8766.0)),0) AS AverageAge
Notice, the ROUND is outside rather than inside. This will allow for the AVG to be more accurate and we ROUND only once. Making it faster too.
SELECT ID,
Name,
DATEDIFF(yy,CONVERT(DATETIME, DOB),GETDATE()) AS AGE,
DOB
FROM MyTable
Here is a technique which seems to work around the edge cases: the end of the year and leap Februaries.
The problem with datediff(year,…,…) is that it only finds the difference between the years, and not the actual dates, which is a bit naïve in my opinion. This is only reliable if the date of birth is 1st Jan.
The solution is to time warp the date of birth to the first of January, and the asking date by the same amount.
Because of the leap year problem using the day of year is also unreliable, so I use the month and day to do the time warp:
CREATE FUNCTION age(@then AS date,@now AS date) RETURNS int AS
BEGIN
DECLARE @month INT = month(@then)-1;
DECLARE @day INT = day(@then)-1;
SET @then=dateadd(month,-@month,@then);
SET @then=dateadd(day,-@day,@then);
SET @now=dateadd(month,-@month,@now;)
SET @now=dateadd(day,-@day,@now);
RETURN datediff(year,@then,@now);
END;
You can write this more compactly, of course. You can even write it in one line, if that’s your idea of having a good time:
CREATE FUNCTION age(@then AS date,@now AS date) RETURNS int AS
BEGIN
RETURN datediff(
year,
dateadd(day,-day(@then)+1,dateadd(month,-month(@then)+1,@then)),
dateadd(day,-day(@then)+1,dateadd(month,-month(@then)+1,@now))
);
END;
but that’s only showing off, and it’s less efficient as it needs to recalculate the offsets.
Gotta throw this one out there. If you convert the date using the 112 style (yyyymmdd) to a number you can use a calculation like this...
(yyyyMMdd - yyyyMMdd) / 10000 = difference in full years
declare @as_of datetime, @bday datetime;
select @as_of = '2009/10/15', @bday = '1980/4/20'
select
Convert(Char(8),@as_of,112),
Convert(Char(8),@bday,112),
0 + Convert(Char(8),@as_of,112) - Convert(Char(8),@bday,112),
(0 + Convert(Char(8),@as_of,112) - Convert(Char(8),@bday,112)) / 10000
output
20091015 19800420 290595 29
What about a solution with only date functions, not math, not worries about leap year
CREATE FUNCTION dbo.getAge(@dt datetime)
RETURNS int
AS
BEGIN
RETURN
DATEDIFF(yy, @dt, getdate())
- CASE
WHEN
MONTH(@dt) > MONTH(GETDATE()) OR
(MONTH(@dt) = MONTH(GETDATE()) AND DAY(@dt) > DAY(GETDATE()))
THEN 1
ELSE 0
END
END
DECLARE @FromDate DATETIME = '1992-01-2623:59:59.000',
@ToDate DATETIME = '2016-08-10 00:00:00.000',
@Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME
SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)
- (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),
@FromDate) > @ToDate THEN 1 ELSE 0 END)
SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)
SET @Months = DATEDIFF(MONTH, @tmpFromDate, @ToDate)
- (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),
@tmpFromDate) > @ToDate THEN 1 ELSE 0 END)
SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)
SET @Days = DATEDIFF(DAY, @tmpFromDate, @ToDate)
- (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),
@tmpFromDate) > @ToDate THEN 1 ELSE 0 END)
SELECT @FromDate FromDate, @ToDate ToDate,
@Years Years, @Months Months, @Days Days
Just check whether the below answer is feasible.
DECLARE @BirthDate DATE = '09/06/1979'
SELECT
(
YEAR(GETDATE()) - YEAR(@BirthDate) -
CASE WHEN (MONTH(GETDATE()) * 100) + DATEPART(dd, GETDATE()) >
(MONTH(@BirthDate) * 100) + DATEPART(dd, @BirthDate)
THEN 1
ELSE 0
END
)
I believe this is similar to other ones posted here.... but this solution worked for the leap year examples 02/29/1976 to 03/01/2011 and also worked for the case for the first year.. like 07/04/2011 to 07/03/2012 which the last one posted about leap year solution did not work for that first year use case.
SELECT FLOOR(DATEDIFF(DAY, @date1 , @date2) / 365.25)
Found here.
This will correctly handle the issues with the birthday and rounding:
DECLARE @dob datetime
SET @dob='1992-01-09 00:00:00'
SELECT DATEDIFF(YEAR, '0:0', getdate()-@dob)
select DATEDIFF(yy,@DATE,GETDATE()) -
case when DATEPART(mm,GETDATE())*100+DATEPART(dd,GETDATE())>=
DATEPART(mm,@DATE)*100+DATEPART(dd,@DATE) THEN 0
ELSE 1 END
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
I've done a lot of thinking and searching about this and I have 3 solutions that
Here are testing values:
DECLARE @NOW DATETIME = '2013-07-04 23:59:59'
DECLARE @DOB DATETIME = '1986-07-05'
Solution 1: I found this approach in one js library. It's my favourite.
DATEDIFF(YY, @DOB, @NOW) -
CASE WHEN DATEADD(YY, DATEDIFF(YY, @DOB, @NOW), @DOB) > @NOW THEN 1 ELSE 0 END
It's actually adding difference in years to DOB and if it is bigger than current date then subtracts one year. Simple right? The only thing is that difference in years is duplicated here.
But if you don't need to use it inline you can write it like this:
DECLARE @AGE INT = DATEDIFF(YY, @DOB, @NOW)
IF DATEADD(YY, @AGE, @DOB) > @NOW
SET @AGE = @AGE - 1
Solution 2: This one I originally copied from @bacon-bits. It's the easiest to understand but a bit long.
DATEDIFF(YY, @DOB, @NOW) -
CASE WHEN MONTH(@DOB) > MONTH(@NOW)
OR MONTH(@DOB) = MONTH(@NOW) AND DAY(@DOB) > DAY(@NOW)
THEN 1 ELSE 0 END
It's basically calculating age as we humans do.
Solution 3: My friend refactored it into this:
DATEDIFF(YY, @DOB, @NOW) -
CEILING(0.5 * SIGN((MONTH(@DOB) - MONTH(@NOW)) * 50 + DAY(@DOB) - DAY(@NOW)))
This one is the shortest but it's most difficult to understand. 50 is just a weight so the day difference is only important when months are the same. SIGN function is for transforming whatever value it gets to -1, 0 or 1. CEILING(0.5 * is the same as Math.max(0, value) but there is no such thing in SQL.
You need to consider the way the datediff command rounds.
SELECT CASE WHEN dateadd(year, datediff (year, DOB, getdate()), DOB) > getdate()
THEN datediff(year, DOB, getdate()) - 1
ELSE datediff(year, DOB, getdate())
END as Age
FROM <table>
Which I adapted from here.
Note that it will consider 28th February as the birthday of a leapling for non-leap years e.g. a person born on 29 Feb 2020 will be considered 1 year old on 28 Feb 2021 instead of 01 Mar 2021.
Try this solution:
declare @BirthDate datetime
declare @ToDate datetime
set @BirthDate = '1/3/1990'
set @ToDate = '1/2/2008'
select @BirthDate [Date of Birth], @ToDate [ToDate],(case when (DatePart(mm,@ToDate) < Datepart(mm,@BirthDate))
OR (DatePart(m,@ToDate) = Datepart(m,@BirthDate) AND DatePart(dd,@ToDate) < Datepart(dd,@BirthDate))
then (Datepart(yy, @ToDate) - Datepart(yy, @BirthDate) - 1)
else (Datepart(yy, @ToDate) - Datepart(yy, @BirthDate))end) Age
CASE WHEN datepart(MM, getdate()) < datepart(MM, BIRTHDATE) THEN ((datepart(YYYY, getdate()) - datepart(YYYY, BIRTH_DATE)) -1 )
ELSE
CASE WHEN datepart(MM, getdate()) = datepart(MM, BIRTHDATE)
THEN
CASE WHEN datepart(DD, getdate()) < datepart(DD, BIRTHDATE) THEN ((datepart(YYYY, getdate()) - datepart(YYYY, BIRTHDATE)) -1 )
ELSE (datepart(YYYY, getdate()) - datepart(YYYY, BIRTHDATE))
END
ELSE (datepart(YYYY, getdate()) - datepart(YYYY, BIRTHDATE)) END
END
Try This
DECLARE @date datetime, @tmpdate datetime, @years int, @months int, @days int
SELECT @date = '08/16/84'
SELECT @tmpdate = @date
SELECT @years = DATEDIFF(yy, @tmpdate, GETDATE()) - CASE WHEN (MONTH(@date) > MONTH(GETDATE())) OR (MONTH(@date) = MONTH(GETDATE()) AND DAY(@date) > DAY(GETDATE())) THEN 1 ELSE 0 END
SELECT @tmpdate = DATEADD(yy, @years, @tmpdate)
SELECT @months = DATEDIFF(m, @tmpdate, GETDATE()) - CASE WHEN DAY(@date) > DAY(GETDATE()) THEN 1 ELSE 0 END
SELECT @tmpdate = DATEADD(m, @months, @tmpdate)
SELECT @days = DATEDIFF(d, @tmpdate, GETDATE())
SELECT Convert(Varchar(Max),@years)+' Years '+ Convert(Varchar(max),@months) + ' Months '+Convert(Varchar(Max), @days)+'days'
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
select floor((datediff(day,0,@today) - datediff(day,0,@birthdate)) / 365.2425) as age
There are a lot of 365.25 answers here. Remember how leap years are defined:
Declare @dob datetime
Declare @today datetime
Set @dob = '05/20/2000'
set @today = getdate()
select CASE
WHEN dateadd(year, datediff (year, @dob, @today), @dob) > @today
THEN datediff (year, @dob, @today) - 1
ELSE datediff (year, @dob, @today)
END as Age
Here is how i calculate age given a birth date and current date.
select case
when cast(getdate() as date) = cast(dateadd(year, (datediff(year, '1996-09-09', getdate())), '1996-09-09') as date)
then dateDiff(yyyy,'1996-09-09',dateadd(year, 0, getdate()))
else dateDiff(yyyy,'1996-09-09',dateadd(year, -1, getdate()))
end as MemberAge
go
What about:
DECLARE @DOB datetime
SET @DOB='19851125'
SELECT Datepart(yy,convert(date,GETDATE())-@DOB)-1900
Wouldn't that avoid all those rounding, truncating and ofsetting issues?
Ed Harper's solution is the simplest I have found which never returns the wrong answer when the month and day of the two dates are 1 or less days apart. I made a slight modification to handle negative ages.
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
you should use
select FLOOR(DATEDIFF(CURDATE(),DATE(DOB))/365.25) from table_name;
here CURDATE() uses current date you can give own date in 'yyyy-mm-dd' format
DATE(DOB) extract yyyy-mm-dd year from your column which is in DATETIME format
here DOB is your column name (but you should alter table to modify the data type to be DATETIME in your case which is nvarchar)
Note-
this query is used in mysql
this return age in whole year
DECLARE @DOB datetime
set @DOB ='11/25/1985'
select floor(
( cast(convert(varchar(8),getdate(),112) as int)-
cast(convert(varchar(8),@DOB,112) as int) ) / 10000
)
source: http://beginsql.wordpress.com/2012/04/26/how-to-calculate-age-in-sql-server/
SELECT CAST(DATEDIFF(dy, @DOB, GETDATE()+1)/365.25 AS int)
After trying MANY methods, this works 100% of the time using the modern MS SQL FORMAT function instead of convert to style 112. Either would work but this is the least code.
Can anyone find a date combination which does not work? I don't think there is one :)
--Set parameters, or choose from table.column instead:
DECLARE @DOB DATE = '2000/02/29' -- If @DOB is a leap day...
,@ToDate DATE = '2018/03/01' --...there birthday in this calculation will be
--0+ part tells SQL to calc the char(8) as numbers:
SELECT [Age] = (0+ FORMAT(@ToDate,'yyyyMMdd') - FORMAT(@DOB,'yyyyMMdd') ) /10000
DECLARE @yourBirthDate DATETIME = '1987-05-25'
SELECT YEAR(DATEADD(DAY, DATEDIFF(DAY, @yourBirthDate, GETDATE()), CAST('0001-01-01' AS DATETIME2))) - 1
How about this:
SET @Age = CAST(DATEDIFF(Year, @DOB, @Stamp) as int)
IF (CAST(DATEDIFF(DAY, DATEADD(Year, @Age, @DOB), @Stamp) as int) < 0)
SET @Age = @Age - 1
Source: Stackoverflow.com