题目

1、题目

#第一题
select city_id,count(clue_id),avg(price)
from tbl_clue 
where date(created_at)="2016-6-7" 
GROUP BY city_id
ORDER BY count(clue_id) DESC
#第二题
select city_name,count(clue_id),avg(price)
from tbl_clue INNER JOIN tbl_city 
on date(created_at)="2016-6-7" and tbl_clue.city_id=tbl_city.city_id
GROUP BY tbl_clue.city_id
ORDER BY count(tbl_clue.clue_id) DESC
#第三题