Employee Total Experience SQL query - sql

Question

I have table with employees work experience. I want to get summary experience in format like yy mm dd.
e_id work_from work_to
2 2003-10-13 2004-02-12
2 2004-02-16 2004-06-30
2 2004-07-01 2006-01-31
2 2006-02-01 2017-07-12
Result should be: 13Y 8M 27D
Query like:
sum(datediff(month,work_from,work_to))/12,
sum(datediff(month,work_from,work_to)%12
works fine, but what about days?

Answer 1

Please note, the following query is a general summation which does not include leap years and the months are averaged between 365/12 in days since the amount of days in each month vary. If you want an exact figure that includes the exact amount of days, the algorithm will be more involved, but hopefully this gets you in a reasonably close ballpark figure.
SELECT CONVERT(VARCHAR(10), sum(datediff(year,work_from,work_to))-1) + 'Y' AS Years,
CONVERT(VARCHAR(10), FLOOR((sum(datediff(day, work_from,work_to)) - ((sum(datediff(year,work_from,work_to)) - 1) * 365)) / 30.4166)) + 'M' AS Months,
CONVERT(VARCHAR(10), CEILING(sum(datediff(day, work_from,work_to)) - ((sum(datediff(year,work_from,work_to)) - 1) * 365) - (FLOOR((sum(datediff(day, work_from,work_to)) - ((sum(datediff(year,work_from,work_to)) - 1) * 365)) / 30.4166) * 30.4166))) + 'D' AS Days,
CONVERT(VARCHAR(10), sum(datediff(day,work_from,work_to))) AS Total_Days

Answer 2

Here is my solution. This is the closest I can get. The problem that I had is that I cant escape the M after month.
DECLARE #SumExp Datetime = (SELECT CONCAT(
DATENAME(day, (SELECT SUM(DATEDIFF(day, WorkFrom, WorkTo))
FROM EmployeeWorkExperience)),
DATENAME(month, (SELECT SUM(DATEDIFF(day, WorkFrom, WorkTo))
FROM EmployeeWorkExperience)),
DATENAME(year, (SELECT SUM(DATEDIFF(day, WorkFrom, WorkTo))
FROM EmployeeWorkExperience))))
SELECT REPLACE(FORMAT(#SumExp, 'yyY MM# ddD'), '#', 'M')

Answer 3

DECLARE #work TABLE(
WorkId INT IDENTITY(1,1) PRIMARY KEY ,
work_from DATETIME NOT NULL,
work_to DATETIME NOT NULL )
INSERT INTO #work
( work_from, work_to )
VALUES ( '10/13/2003',
'2/12/2004'
),
(
'2/16/2004',
'6/30/2004'
),
('7/1/2004',
'1/31/2006'
),
('2/1/2006',
'7/12/2017'
)
DECLARE #seconds int
SELECT #seconds = SUM(DATEDIFF(SECOND, work_from, work_to))
FROM #work
DECLARE #VARDT DATETIME = DATEADD(SECOND, #seconds, 0)
SELECT CAST(DATEPART(YEAR, #VARDT) - 1900 AS VARCHAR(10)) + ' year(s) ' + CAST(DATEPART(MONTH, #VARDT) - 1 AS VARCHAR(2)) + ' month(s) '
+ CAST(DATEPART(DD, #VARDT) - 1 AS VARCHAR(2)) + ' day(s) ' + CAST(DATEPART(HOUR, #VARDT) AS VARCHAR(2)) + ' hour(s) '
+ CAST(DATEPART(MINUTE, #VARDT) AS VARCHAR(2)) + ' minute(s) ' + CAST(DATEPART(SECOND, #VARDT) AS VARCHAR(2)) + ' second(s)'