在 SQLITE 3 中按国家/地区选择收入排名前 3 的艺术家

Question

我有多个表格，分别是艺术家、专辑、曲目、invoice_items、invoices、customers。

我在下面写了sql查询：

select country, artistid, name, revenue from 
(select t6.country, t1.artistid, t1.name, sum(t4.quantity*t4.unitprice) as revenue 
from artists 
t1 inner join albums t2 
inner join tracks t3 
inner join invoice_items t4 
inner join invoices t5 
inner join customers t6 on t1.artistid=t2.artistid 
and t2.albumid=t3.albumid 
and t3.trackid=t4.trackid 
and t4.invoiceid=t5.invoiceid 
and t5.customerid=t6.customerid 
group by t6.country, t1.artistid 
);

查询的输出：

预期输出： 每个国家/地区按收入排序的前 3 名艺术家。因为我需要分别获得阿根廷、澳大利亚、巴西、美国的前三名。

Answer 1

使用排名函数：

SELECT * FROM 
  (SELECT ARTISTID,
               NAME,
               COUNTRY,
               REVENUE,
               RANK () OVER (PARTITION BY COUNTRY ORDER BY REVENUE DESC) RANK
          FROM ARTISTS)
 WHERE RANK < 4

https://www.sqlite.org/windowfunctions.html

Answer 2

一个选项使用相关子查询来确定每个国家/地区的前 5 个收入来源。为方便起见，您可以将当前查询放入可重复使用的 CTE：

WITH yourTable AS (
    SELECT t6.country, t1.artistid, t1.name, SUM(t4.quantity*t4.unitprice) AS revenue
    FROM artists t1
    INNER JOIN albums t2 ON t1.artistid = t2.artistid
    INNER JOIN tracks t3 ON t2.albumid = t3.albumid
    INNER JOIN invoice_items t4 ON t3.trackid = t4.trackid
    INNER JOIN invoices t5 ON t4.invoiceid = t5.invoiceid
    INNER JOIN customers t6 ON t5.customerid = t6.customerid
    GROUP BY t6.country, t1.artistid, t1.name
)

SELECT t1.*
FROM yourTable t1
WHERE artistid IN (
    SELECT t2.artistid
    FROM yourTable t2
    WHERE t1.country = t2.country
    ORDER BY t2.revenue DESC, t2.name
    LIMIT 5
)
ORDER BY
    country, revenue DESC;

Demo

请注意，我在LIMIT 子查询中按名称添加了订单级别。这是为了明确打破平局，如果两个或多个艺术家碰巧在给定国家有相同的收入。在这种情况下，按字母顺序较早的名称是最先显示的名称。