Number of comments per pull request

select avg(num_comments), project_name, url
from
(
	(select count(pull_request_comments.comment_id) as num_comments, projects.id as project_id, projects.name as project_name, projects.url as url, pull_requests.id as pull_request_id
	from pull_request_comments
		join pull_requests on pull_requests.id = pull_request_comments.pull_request_id
		join projects on projects.id = pull_requests.base_repo_id
	group by projects.id, pull_requests.id) comment_nums
)
group by project_id

GHData