I'm writing a query to look for courses that do not have any of its gradable items graded.
In Blackboard when a user doesn't have a grade at all(e.g. no attempt was ever made) there simply isn't a row in the table gradebook_grade
So if a course doesn't have any grades at all the gradebook_grade table does not have any rows referencing the primary key of the Blackboard course_id
This is what I've used so far:
from course_main cm
join gradebook_main gbm on cm.pk1 = gbm.crsmain_pk1
join gradebook_grade gbg on gbm.pk1 = gbg.gradebook_main_pk1
where cm.pk1 = 3947
group by cm.course_id
having count(gbg.pk1) <= 0
The course in question(pk1 3947) is confirmed to not have any grades. So SQL Server says 0 rows affected, naturally.
The thing is, it doesn't select the course_id. I'm guessing having doesn't account for blank/non-existent rows. Is there a way to structure the query to get the course ID when there isn't anything returned? Am I joining on the wrong columns or using where on the wrong column?
Any help would be appreciated!