mysql query order by multiple items

Question

is is possible to order by multiple rows?

I want my users to be sorted by last_activity, but at the same time, i want the users with pictures to appear before the ones without

Something like this:

SELECT some_cols
FROM `prefix_users`
WHERE (some conditions)
ORDER BY last_activity, pic_set DESC;

Answer 1

SELECT some_cols
FROM prefix_users
WHERE (some conditions)
ORDER BY pic_set DESC, last_activity;

Answer 2

Sort by picture and then by activity:

SELECT some_cols
FROM `prefix_users`
WHERE (some conditions)
ORDER BY pic_set, last_activity DESC;

Answer 3

SELECT id, user_id, video_name
FROM sa_created_videos
ORDER BY LENGTH(id) ASC, LENGTH(user_id) DESC