need to calculate year,month and day for closing date - sql

Question

I have a table called dates,
Opendate | Closedate
------------+---------------
2015-07-09 | 2016-08-10
I am expecting the output like,
opendate | closedate | diff
------------+---------------+----------------------
2015-07-09 | 2016-08-10 | 1year 1month 1day
2015-07-09 | 2016-03-01 | 8 months 20 days
2015-07-09 | 2015-07-11 | 2 days
But when I run this query:
SELECT opendate,
closedate,
Datediff(year, opendate, closedate) AS years,
Datediff(month, opendate, closedate) AS months,
Datediff(day, opendate, closedate) AS days
FROM dates
It is giving me an output like,
opendate | closedate | years | months | days
------------+---------------+-------+--------+---------
2015-07-09 | 2016-08-10 | 1 | 13 | 397
How can we calculate 1 year 1 month and 1 day

Answer 1

You can use Stacked CTE to find one by one the next year, month and date.
Explanation
Query Below first finds out the DATEDIFF Years of opendate and closedate and checks if the resulting date is greater than closedate. if it is, the actual year difference is DATEDIFF of Y -1. use this new date and fetch the DATEDIFF of months using the same logic and then get the difference in days.
Online Example
Query
WITH D(Opendate,Closedate)AS
(
SELECT CAST('2015-07-09' AS DATE),CAST('2016-08-10' AS DATE)
UNION ALL
SELECT CAST('2015-07-09' AS DATE),CAST('2016-03-01' AS DATE)
UNION ALL
SELECT CAST('2015-07-09' AS DATE),CAST('2015-07-11' AS DATE)
),Y AS
(
SELECT Opendate,Closedate,
CASE
WHEN DATEADD(YEAR,DATEDIFF(YEAR,Opendate,Closedate),Opendate) > Closedate
THEN DATEDIFF(YEAR,Opendate,Closedate) - 1
ELSE DATEDIFF(YEAR,Opendate,Closedate)
END Years
FROM D
), YDate as
(
SELECT Opendate,Closedate,Years,DATEADD(YEAR,Years,Opendate) as Newopendate
FROM Y
),M AS
(
SELECT Opendate,Closedate,Years,Newopendate,
CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH,Newopendate,Closedate),Newopendate) > Closedate
THEN DATEDIFF(MONTH,Newopendate,Closedate) - 1
ELSE DATEDIFF(MONTH,Newopendate,Closedate)
END Months
FROM YDate
)
SELECT Opendate,Closedate,Years,Months,DATEDIFF(Day,DATEADD(MONTH,Months,Newopendate),Closedate) as days
FROM M
Result
Opendate Closedate Years Months days
09-07-2015 00:00 10-08-2016 00:00 1 1 1
09-07-2015 00:00 01-03-2016 00:00 0 7 21
09-07-2015 00:00 11-07-2015 00:00 0 0 2

Answer 2

SELECT opendate,
closedate,
( ( Datediff(year, opendate, closedate) + 'years' )+
(( Datediff(month, opendate, closedate) -
12 * Datediff(year, opendate, closedate)) + 'months') +
( Datediff(day, opendate, closedate) -
( Datediff(year, opendate, closedate) * 365 -
(Datediff(month, opendate, closedate) * 12) )) + 'days'
FROM dates
The logic is you concatenate the years and then deduct the no of months of a year. Similarly deduct for days as well

Answer 3

Create one function as Below
CREATE FUNCTION dbo.GetYearMonthDays
(
#FromDate DATETIME
)
RETURNS NVARCHAR(100)
AS
BEGIN
DECLARE #date datetime, #tmpdate datetime, #years int, #months int, #days int
SELECT #date =#FromDate
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())
RETURN CONVERT(varchar(10), #years) +' Years ' + CONVERT(varchar(10), #months) + ' Month ' + CONVERT(varchar(10), #days) + ' Days'
END
GO
And use is as below
SELECT opendate,
closedate,dbo.GetYearMonthDays(closedate)
FROM dates
This will give you what you wants.