无效的标识符错误，甲骨文

Question

我一直在试图写这个查询1小时，但SQL Developer始终引发错误。

SELECT d.driver_name, COUNT(*) AS cnt 
    FROM Drivers d 
    JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
    GROUP BY d.driver_name 
    HAVING cnt = MAX(cnt); 

00000 - “％S：无效识别符” 在最后一行

错误，柱20

所以我已经找到了另一个解决方案，但又引发了另一个错误：

SELECT d.driver_name, COUNT(*) as cnt 
    FROM Drivers d 
    JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
    GROUP BY d.driver_name 
    HAVING COUNT(*) = MAX(COUNT(*)); 

00000 - “基团功能被嵌套太深”

错误在最后一行中，塔25

编辑：感谢gyus，你是要命，几乎所有的答复都在工作，但我必须选择一个...

Answer 1

使用窗函数：

SELECT driver_name, cnt 
FROM (SELECT d.driver_name, COUNT(*) AS cnt, 
      MAX(COUNT(*)) OVER() as MAXcnt 
     FROM Drivers d JOIN 
      Fastest_laps fl 
      ON d.ID_driver = fl.ID_driver 
     GROUP BY d.driver_name 
    ) d 
WHERE cnt = MAXcnt; 

你也可以使用这种利用RANK()或DENSE_RANK()：

SELECT driver_name, cnt 
FROM (SELECT d.driver_name, COUNT(*) AS cnt, 
      RANK() OVER (ORDER BY COUNT(*) DESC) as seqnum 
     FROM Drivers d JOIN 
      Fastest_laps fl 
      ON d.ID_driver = fl.ID_driver 
     GROUP BY d.driver_name 
    ) d 
WHERE seqnum = 1; 

这种方法的好处是，你可以使用ROW_NUMBER()代替，并得到具体哪一行，甚至如果多个驱动程序有相同的最大值。

Answer 2

试试这个。我按cnt降序排列。然后从中选择最上面一行。您可以将查询编辑为rownum <=2以获得前两排，依此类推。

  with tbl1 as 
      (SELECT d.driver_name as driver_name, COUNT(*) AS cnt 
      FROM Drivers d 
      JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
      GROUP BY d.driver_name 
      order by cnt desc 
      ) 
      select driver_name,cnt from tbl1 
      where cnt = (select cnt from tbl1 rownum=1) 

Answer 3

我不知道，如果Oracle支持这一点，但请给它一个尝试：

SELECT d.driver_name, COUNT(*) as cnt 
FROM Drivers d 
    JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
GROUP BY d.driver_name 
ORDER BY cnt DESC 
FETCH FIRST 1 ROW WITH TIES 

或者使用公用表表达式：

with cte as 
(
SELECT d.driver_name as driver_name, COUNT(*) AS cnt 
FROM Drivers d 
    JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
GROUP BY d.driver_name 
) 
select driver_name, cnt 
from cte 
where cnt = (select max(cnt) from cte) 

Answer 4

你有你的包裹查询到内联视图以便能够查询cnt：

select * 
from (
     SELECT d.driver_name, COUNT(*) AS cnt 
     FROM Drivers d 
     JOIN Fastest_laps fl ON d.ID_driver = fl.ID_driver 
     GROUP BY d.driver_name 
     ) x 
group 
by  driver_name, cnt 
having cnt = MAX(cnt);