select university,
avg(question_cnt) as avg_question_cnt,//平均
avg(answer_cnt) as avg_answer_cnt//平均
from user_profile
group by university//每个学校
having avg_question_cnt < 5 //having + 分组后删选的条件
or
avg_answer_cnt < 20;
select university,
avg(question_cnt) as avg_question_cnt,//平均
avg(answer_cnt) as avg_answer_cnt//平均
from user_profile
group by university//每个学校
having avg_question_cnt < 5 //having + 分组后删选的条件
or
avg_answer_cnt < 20;