mysql 的 子查询

SELECT `name`,avg(score) avg FROM score WHERE `name` IN ( SELECT `name` FROM score WHERE score < 60 GROUP BY `name` HAVING  COUNT(name) >= 2 ) GROUP BY name

SELECT `name`,AVG(score)avg,SUM(IF(score<60,1,0)) c FROM score GROUP BY `name` HAVING c >= 2

SELECT `name`,AVG(score) avg,SUM(score<60) c FROM score GROUP BY `name` HAVING c >= 2