员工:
| id | name | department | managerId |
+-----+-------+------------+-----------+
| 101 | John | A | null |
| 102 | Dan | A | 101 |
| 103 | James | A | 101 |
| 104 | Amy | A | 101 |
| 105 | Anne | A | 101 |
| 106 | Ron | B | 101 |
+-----+-------+------------+-----------|
从上面的员工表中，我们需要管理至少5名员工的经理的姓名. 我提出了这个疑问:
select name from employee where managerid in (
select managerid
from employee
where managerid is not null
group by managerid having count(*) > 4
);
我预计会有以下输出:
| name |
+------+
| John |
+------+
但相反，它却抛出了:
| ----- |
| Dan |
| James |
| Amy |
| Anne |
| Ron |
where分句将manager id返回为101.但最终的 Select 并不是拿起相应的名字.哪里出了问题？