My question is similar to this one: Compare rows and get percentage However, little different. I adapted my question to the other post. I got 2 tables. First table: user_id | post_id 1 1 1 2 1 3 2 12 2 15 And second table: post_id | rating 1 1 1 2 1 3 2 1 2 5 3 null 3 1 3 4 12 4 15 1 So now I would like to count the rating for each post, in the second table. If the rating has more than, lets say, 50% positive ratings than I want to get the post_id and going it to the post_id from table one and add 1 to the user_id. At the end it would return the user_id with the number of positive posts. The result for above table would be: user_id | helpfulPosts 1 2 2 1 The post with post_id 1 and 3 have positive rating, because more than 50% have ratings of 1-3. The post with id = 2 is not positive, because the rating is exactly 50%. How would I achieve this? For clarification: It's a mysql rdbm and a positive post, is one where the number of rating_ids with 1, 2 and 3 are more than half of the overall rating. Basically the same thing, from the other thread I posted above.