Question

I am making a DATEDIFF() call in SQL server 2008 as part of a stored procedure, which potentially is returning values of as small as 3 seconds or less. I would like the format to be in MM:SS (i.e. 00:03 when 3 seconds). I was originally using the call in minutes:

DATEDIFF(mi, SELECT MAX(startDate) FROM myTable , SELECT MAX(EndDate) FROM myTable)

However, this was rounding down to the nearest minute, and thus erasing the seconds values. How can I achieve a format as specified above using DATEDIFF?

Answer 1

To the nearest second:

DATEDIFF(ss, SELECT MAX(startDate) FROM myTable, SELECT MAX(EndDate) FROM myTable)

Ref.

Note: DATEDIFF won’t give you a ‘format’. It just returns an integer. So you’ll need to cast/format appropriately.

I suspect the closest you will get easily is using CAST with format 108:

select convert(char(8), dateadd(ss, DATEDIFF(ss, SELECT MAX(startDate) FROM myTable, 
                                                 SELECT MAX(EndDate) FROM myTable)), 
               cast(0 as DateTime)) , 108)

e.g.

select convert(char(8), dateadd(ss, DATEDIFF(ss, '2012-12-16 12:00:00', 
                                                 '2012-12-16 12:13:09'), 
                                cast(0 as DateTime)), 108)

returns:

00:13:09

[Note: If you want to round to the nearest 3 seconds, you could modify this: TSQL: Round to Nearest 15 Minute Interval ]