Ah, I spoke too soon! This sort of does what I want, but how do I tell it to return the number of comments for each individual row returned? At the moment, I can only tell it to return the total amount of comments. Is there a mysql command that lets you do it for a particular row? Here's an example of my query:
SELECT `blog_posts`.`id`, `blog_posts`.`user_id`, `blog_posts`.`title`, `blog_posts`.`body`, `blog_posts`.`created`, `blog_posts`.`modified`, `users`.`username` AS author,
(SELECT COUNT(*) FROM blog_comments WHERE ?what do i put here?) AS num_coms
FROM (`blog_posts`)
LEFT JOIN `users` ON `users`.`id` = `blog_posts`.`user_id`
ORDER BY `created` DESC
LIMIT 10