MySQL: To exclude some results based on specified conditions -

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i stuck @ problem. problem has 2 tables, namely hackers , challenges. here schema:

hackers(hacker_id: int, name string) challenges(challenge_id: int, hacker_id int)

i trying write query print hacker_id, name, , total number of challenges created each student. sort results total number of challenges in descending order. if more 1 student created same number of challenges, sort result hacker_id. if more 1 student created same number of challenges , count less maximum number of challenges created, exclude students result.

here query: 

select hackers.hacker_id ,         hackers.name ,         count(challenges.challenge_id) challenges_created                 hackers left join  challenges         on         hackers.hacker_id = challenges.hacker_id          having         count(challenges_created) >= max(challenges_created)         order challenges_created desc, hackers.hacker_id asc

i getting wrong output! please tell me getting wrong!

sample input :

hackers table:image challengers table :image 

sample output: 21283  angela  6 88255  patrick  5 96196  lisa  1

this not real answer, start point you:

http://sqlfiddle.com/#!9/6910c/5

select h.hacker_id ,         h.name ,         count(challenges.challenge_id) challenges_created   hackers h  left join challenges  on  h.hacker_id = challenges.hacker_id   group h.hacker_id #having challenges_created >= max(challenges_created)  order challenges_created desc, h.hacker_id asc

i've commented out having clause, because can not understand trying achieve.

explain please why expect 3 rows in result? why rose , frank should excluded result set?


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