查询某条件下记录数大于N的数据

需求，查询记录数大于20的user_id的所有数据

第一种 子查询+in查询：

SELECT * FROM
`table_name`
WHERE user_id in (SELECT user_id FROM `table_name` group by user_id having count(user_id) > 10)

第二种 子查询+join查询：

SELECT * FROM
`table_name` AS T
 JOIN (SELECT user_id, count(1) as num  FROM `table_name` group by user_id having num > 10) AS M ON  T.user_id = M.user_id

经过测试，子查询+join查询效率更高！