Sql 查找下属人数最多的经理姓名

我需要为Oracle编写SQL查询，该查询显示具有最大下属数的经理姓名

表的结构：

EMPNO INT PRIMARY KEY
ENAME VARCHAR NOT NULL
MGR_ID INT

经理ID员工属性是经理的临时主密钥

到目前为止，我所尝试的：

SELECT ENAME FROM EMP WHERE 
(SELECT COUNT(MGR_ID) FROM EMP GROUP BY MGR_ID)=
(SELECT MAX(SELECT COUNT(MGR_ID) FROM EMP GROUP BY MGR_ID) FROM EMP);

另一个版本由一匹没有名字的马建议

SELECT e.ename FROM
   emp e
   INNER JOIN 
     ( 
      SELECT mgr_id, DENSE_RANK () OVER (ORDER BY COUNT (*) DESC) rnk
        FROM emp
    GROUP BY mgr_id
    )list
   ON ( list.mgr_id=e.empno)
  WHERE  list.rnk=1

PS:查询未测试

解决方案为

with temp_tab as
(
select mgr_id, count(*) num_emp from emp group by mgr_id order by 2 desc
)
select * from temp_tab where rownum<=1;

---

您可以通过组合窗口函数和聚合来简化这一过程：选择mgr_id，densite_rank over order by count*desc from emp group by mgr_id-请开始使用显式连接，而不是where中旧的、过时的隐式连接clause@a_horse_with_no_name谢谢你，先生，我以后会处理的。

with temp_tab as
(
select mgr_id, count(*) num_emp from emp group by mgr_id order by 2 desc
)
select * from temp_tab where rownum<=1;