sql query date difference between two dates

Question

I am trying to do something I don't know if it's doable. I have this query:

SELECT [CreatedOn]
FROM [MyTable]

As you can see in the image, there are different dates. Now what I want to achieve is to get the time difference between each date/time in each row. For example, diference between date in row1 and row2, then row2 and row3, etc... Is that possible? Thanks, Laziale

Answer 1

You can create a cte with row number then outer join on the next row to get the datediff

;with t as (
    SELECT 
        [CreatedOn],
        rn = row_number() over(order by [CreatedOn])
    FROM 
        [MyTable]
)

select
    t.[CreatedOn],
    secondsTilNext = datediff(s, t.[CreatedOn], tnext.[CreatedOn])
from
    t
    left outer join t tnext on tnext.rn = t.rn + 1

Answer 2

;WITH q AS (
SELECT
    CreatedOn,
    ROW_NUMBER() OVER (ORDER BY CreatedOn) AS rn
FROM
    MyTable
)
SELECT
    q1.CreatedOn AS Date,
    q2.CreatedOn AS NextDate,
    DATEDIFF(SECOND, q1.CreatedOn, q2.CreatedOn) AS SecondDiff
FROM 
    q q1 JOIN
    q q2 ON q1.rn + 1 = q2.rn

Answer 3

Assuming you are using C# to access your data, there is a good reference here: http://msdn.microsoft.com/en-us/library/aa287590(v=vs.71).aspx

Basically, the code is

DateTime oldDate = new DateTime(2002,7,15);
DateTime newDate = DateTime.Now;
// Difference in days, hours, and minutes.
TimeSpan ts = newDate - oldDate;
// Difference in days.
int differenceInDays = ts.Days;

Any .NET language you use should support something similar to this. I've done the same thing in Python many times.

Answer 4

Try datediff MSDN Datediff

Or perhaps

    cast((date1-date2) as varchar(255))

Syntax might be wrong, I can't check it at the moment.