SQL To Find Most Popular Category

Question

I have 3 tables in my DB (MySQL).

categories (name:string)
items (name:string, category_id:int)
votes (value:int, item_id:int, created_at:datetime)
         


        

Answer 1

SELECT c.name, sum(v.value) as cnt
 FROM categories c
 JOIN items i ON i.category_id = c.id
 JOIN votes v ON v.item_id = i.id
 WHERE v.created_at > #{1.week.ago}
 GROUP BY c.name 
 ORDER BY cnt DESC LIMIT 5;

Edit: good point andrew, I fixed the query