Question

好的，所以我在Oracle中有两个表：

CAR，具有属性所有者（引用EMPLOYEE（ssn））

EMPLOYEE，具有属性名称，ssn。

我需要获得具有最大数量汽车的员工的姓名和ssn，但我无法理解如何以这种方式使用聚合函数......

我尝试过以下内容：

    SELECT name, ssn
    FROM EMPLOYEE
    WHERE ssn IN (SELECT owner
                  FROM CAR
                  HAVING COUNT(owner) = MAX(COUNT(owner))
                  GROUP BY owner)

但它似乎没有返回任何东西......我是否在正确的轨道上？

Answer 1

select e.name,e.ssn,count(*)
from EMPLOYEE e 
inner join CAR c on e.ssn = c.owner
group by e.name,e.ssn

Answer 2

select * from EMPLOYEE
where ssn = (
  select min(owner) keep (dense_rank first order by count(1) desc, owner) 
  from CAR 
  group by owner
)

fiddle

使用Oracle中的max函数查找记录

2 个答案: