Drill 6: Write a test — Joins and aggregates

select
  c.slug,
  c.title,
  count(l.id) as lesson_count,
  coalesce(sum(l.minutes), 0) as total_minutes
from courses c
left join lessons l on l.course_slug = c.slug
where c.published = true
group by c.slug, c.title
having count(l.id) >= 3
order by total_minutes desc;