One table contains photos (paths to files that is), and one contains rating data on how much people like the pictures.

simplified..

photo:
pid | name | path
777 | lucky | folder/filename.jpg

photo_has_rating:
pid | voteValue | date
777 | 5 | unixDate
777 | 3 | unixDate
777 | 1 | unixDate


Now I want to select the most popular files (limit x), and the most popular files the last week (limit x).
I'll have to count the voteValues and find the top x popular, and then join with photo, and get the names and paths..

The x most popular ever would be something along the lines:

SELECT t1.name, sum(t2.voteValue) AS totalVotes FROM photo AS t1
INNER JOIN photo_has_rating AS t2 ON t2.pid = t1.pid
GROUP BY t2.voteValue
ORDER BY totalVotes
LIMIT x

If you wanted the the result for the last week you would have to use a WHERE clause