Question

我正在尝试将我的子查询的MAX值表示为NUM_of_CUST列，并将其与tge主查询中的艺术家名称一起显示，以便显示如下：

ARTIST_NAME | NUM_of_CUST

Select A.Lastname ||''|| A.FirstName as Artist_Name from dhey.ARTIST A 
LEFT JOIN
(SELECT * FROM(
SELECT COUNT(*) As Num_of_Customer From Dhey.CUSTOMER_ARTIST_INT CAI
GROUP BY ARTISTID
ORDER BY COUNT(*) desc) WHERE ROWNUM = 1) B on A.ArtistID = B.ArtistID;

然而，SQL正在向我抛出B“。”ARTISTID“：无效的标识符异常。

有人可以就此提出建议吗？

谢谢！

Answer 1

我真的不明白你想做什么，但我认为要么你想要每个艺术家的顾客数量

Select  A.Lastname ||''|| A.FirstName as Artist_Name 
        COUNT(*) as nb_cust
from dhey.ARTIST A 
LEFT outer JOIN Dhey.CUSTOMER_ARTIST_INT B on A.ArtistID = B.ArtistID
group by A.ArtistID, A.Lastname ||''|| A.FirstName
order by nb_cust desc

或者您想要最大的客户总数并将其链接到您的艺术家......这是一行的交叉产品。

Select  A.Lastname ||''|| A.FirstName as Artist_Name 
        nb_cust_max
from dhey.ARTIST A 
cross join  (   select max(nb_cust) as nb_cust_max
                from    (   select count(*) as nb_cust 
                            From Dhey.CUSTOMER_ARTIST_INT 
                            group by ARTISTID
                        )
            )

我关门了吗？还是完全错了？

否则，正如 MatBailie 所示，您只需添加缺少的字段

Select A.Lastname ||''|| A.FirstName as Artist_Name from dhey.ARTIST A 
LEFT JOIN
(SELECT * FROM(
SELECT ARTISTID, COUNT(*) As Num_of_Customer From Dhey.CUSTOMER_ARTIST_INT CAI
GROUP BY ARTISTID
ORDER BY COUNT(*) desc) WHERE ROWNUM = 1) B on A.ArtistID = B.ArtistID;

Answer 2

我用这个解决了我的答案

SELECT A.lastname ||''||A.firstname as Artist_Name, COUNT(CAI.ARTISTID) AS NumberOfCustomers
FROM dhey.CUSTOMER_ARTIST_INT CAI
LEFT JOIN dhey.CUSTOMER C
ON CAI.CUSTOMERID = C.CUSTOMERID
LEFT JOIN dhey.ARTIST A
ON CAI.ARTISTID = A.ARTISTID
group by  A.lastname,  A.firstname
having count(*) = (select max(count(ArtistID))
                     from dhey.CUSTOMER_ARTIST_INT
                    group by ArtistID);

谢谢大家的帮助！

坚持将SQL查询链接在一起

2 个答案: