How do I get average of the duration for multiple weeks.
Currently I get something like
Student Avg completion time Week Year
STUDENT 1 0 1 2013
STUDENT 1 5 1 2013
What I want is
Student Avg completion time Week Year
STUDENT 1 2.5 1 2013
select a.student,avg(a.duration) as "Avg Completion Duration","Week","Year" from (
select a1.student,a1.timecomplete,datepart(week,a1.completiondate) as "Week",datepart(year,a1.completiondate) as "Year" from attendance a1
where year(a1.datetimein)=year(getdate())
union all
select a2.student,a2.timecomplete,datepart(week,a2.completiondate) as "Week",datepart(year,a2.completiondate) as "Year" from attendance a2
where year(a2.datetimein)=year(getdate())-1
group by a2.student,a2.timecomplete,datepart(week,a2.completiondate),datepart(year,a2.completiondate)
) a
group by "Week", a.student,"Avg Completion Duration","Year"