找到最高的金额，尽管有不止一个达到相同的金额

Question

我想为每个国家找到最好的客户，尽管有一个国家有两个相同数量的客户，我希望他们都出现。

select customerid,firstname,lastname,country, max(total_amt)
from (select invoice.customerid, customer.firstname,lastname, 
sum(invoice.total)total_amt,customer.country
  from invoice
   join customer
   on customer.customerid= invoice.customerid
   group by invoice.customerid,customer.country)t2
group by  country;

Answer 1

使用window函数：

select c.*
from (select c.country, c.customerid, c.firstname c.lastname, sum(i.total) as total,
             dense_rank() over (partition by c.country order by sum(i.total) desc) as seqnum
      from customer c join
           invoice i
           on c.customerid = i.customerid
     ) c
where seqnum = 1;

请注意，我还引入了 window 函数，因此查询更易于编写和阅读。

找到最高的金额，尽管有不止一个达到相同的金额

Find the highest amount although there are more than one achieving the same amount

sql

max