Mysql, AVG and Count question

ID,    rating_id , rating_num

33100,   '4028',      2, 
33099,   '4041',      2, 
33098,   '1889',      4, 
33097,   '1889',      5, 
33096,   '4050',      2,
33095,   '8578',      2, 
33094,   '8578',      4,
33093,   '8578',      5,
33093,   '8578',      5,

Guys 3 ques开发者_JS百科tions

1) How can i see which rating_id has received more than three counts of rating_num ? (Answer: 8578)

2) How can i see the average rating_num of each rating_id ?

3) How can i see the average rating_num of each rating_id WHICH received more than three counts of rating_num ? ( Answer: 4 )

Thanks for replying the classs attender of Mysql4dumbmies

---

1

select rating_id
    from YourTable
    group by rating_id
    having count(*) > 3

2

select rating_id, avg(rating_num) as average_rating
    from YourTable
    group by rating_id

3

select rating_id, avg(rating_num) as average_rating
    from YourTable
    group by rating_id
    having count(*) > 3