如何選擇SQL中列中具有最大值的所有記錄？

Question

假設我有以下數據庫：

Create table Employee (emp_id int, emp_name varchar(20), staff int);

Insert into Employee values(101,"John", 3);    
Insert into Employee values(102,"Mary", 3);    
Insert into Employee values(103,"Smith",2);    
Insert into Employee values(104,"Bill", 2);    
Insert into Employee values(105,"Kelly", 1);

我希望它選擇印刷版約翰和瑪麗，因為他們的員工人數最多，即 3。有人能解釋一下嗎？

我試過這樣做：

select emp_name from Employee having staff = max(staff);

但我不斷收到錯誤！

Answer 1

您可以使用返回表的最大員工數的子查詢：

select e.* from Employee e
where e.staff = (select max(staff) from Employee)

Answer 2

= (SELECT MAX(staff) FROM Employee)