DateDiff to output hours and minutes

Question

my code gives TOTAL HOURS in hours, but i am trying to output something like

TotalHours 
  8:36

where 8 represents hour part and 36 repres

Answer 1

No need to jump through hoops. Subtracting Start from End essentially gives you the timespan (combining Vignesh Kumar's and Carl Nitzsche's answers) :

SELECT *,
    --as a time object
    TotalHours = CONVERT(time, EndDate - StartDate),
    --as a formatted string
    TotalHoursText = CONVERT(varchar(20), EndDate - StartDate, 114)
FROM (
    --some test values (across days, but OP only cares about the time, not date)
    SELECT
        StartDate = CONVERT(datetime,'20090213 02:44:37.923'),
        EndDate   = CONVERT(datetime,'20090715 13:24:45.837')
) t

Ouput

StartDate               EndDate                 TotalHours       TotalHoursText
----------------------- ----------------------- ---------------- --------------------
2009-02-13 02:44:37.923 2009-07-15 13:24:45.837 10:40:07.9130000 10:40:07:913

See the full cast and convert options here: https://msdn.microsoft.com/en-us/library/ms187928.aspx