如何按出现时间最多的ID对返回的SQL结果进行排序

Question

I have table offer_cpv that is connecting two others " offer " and " cpv ". You can see fiddle here: http://sqlfiddle.com/#!9/02020/1

offer_cpv has two columns that are important for us: offer_id and cpv_id .

My starting query looks like this: SELECT cpv_id FROM offer_cpv WHERE offer_id IN (1,2,3,4) LIMIT 10

As you can see I need to return all cpv_id based on the array of offer_id ( I pass that to WHERE IN (offer_id) .

I will get this result:

cpv_id
1010
1020
1030
2010
4030
4060
1010
2010
1010
1020

As you can see some cpv_id are repeating because several offers may have same cpv_id linked to them. I need to get list of "most popular" cpv_id, I mean if some id is repeating the most time I need it to be on top of list. For example, this would be desired output:

cpv_id
1010
1020
2010
1030
4030
4060

As you can see 1010 is repeating 3 times so I want it on top of returned result. Then comes 1020 and 2010 since they are repeating 2 times, an then come others until limit of 10 is reached.

Is this possible to do somehow with MYSQL and PHP ?

Thanks

Answer 1

You need count(*) and group by

SELECT cpv_id,count(*) as tot FROM offer_cpv 
WHERE offer_id IN (1,2,3,4) 
group by cpv_id
order by tot desc
LIMIT 10

http://sqlfiddle.com/#!9/02020/3

Answer 2

You can use distinct to get only unique values. Here is your query:

SELECT
    distinct cpv_id
FROM
    offer_cpv
WHERE
    offer_id IN (1,2,3,4)
LIMIT 10