Question

I need some help with a mysql query.

I have 2 tables,

Table 1 – Photos (photo_id, photo_url)

1—– http://www.someurl.com
2—– http://www.someurl.com
3—– http://www.someurl.com
4—– http://www.someurl.com

Table 2 – Favorites (favorite_id, user_id,photo_id)

1——-5——1
2——-5——2
3——-6——1
4——-6——3
5——-7——2
6——-7——3
7——-8——3
7——-8——4

I want to get results from photos table ordering by the favorite numbers of users.

Correct ordering must be:

1) Photo-3 (3 votes)
2) Photo-2 (2 votes)
2) Photo-1 (2 votes)
2) Photo-4 (1 vote)

Answer 1

SELECT  a.photo_url, COUNT(b.photo_ID) totalVotes
FROM    table1 a
        LEFT JOIN table2 b
            ON a.photo_ID = b.photo_id
GROUP BY a.photo_url
ORDER BY totalVotes DESC

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