Contributor breadth is the ratio of non-core committers to core committers. This metric indicates how open a community is to contributions from outsiders. Drive-by committers (also known as one-time committers) do not build rapport with core committers but their contributions might be accepted based on their quality.

In the below queries, non-core committers are defined as committers who do not have commit rights.

Project members have commit rights for the repo.

select count(commits.id) as num_member_commits, projects.name as project_name, projects.url as url
from
commits
join projects on projects.id = commits.project_id
join users on commits.author_id = users.id
join project_members on project_members.repo_id = projects.id
where project_members.user_id = commits.author_id
group by projects.id

select count(commits.id) as num_commits, projects.name as project_name, projects.url as url
from
commits
join projects on commits.project_id = projects.id
join users on users.id = commits.author_id
where (projects.id, users.id) not in
	(select repo_id, user_id from project_members)
group by projects.id