如果在 Postgres 中平局，我如何显示所有结果？

Question

所以，我正在使用 PostgreSQL DBMS，并且有以下查询：

Select "CustomerID",Sum("TotalDue") as Total
from "Bike Business"."SalesOrderHeader" 
group by "CustomerID"
order by Total desc limit 1;

此查询打印订单成本最高的人的ID和最高成本的数量。但是在平局的情况下，2 个或更多人具有相同的最大订单成本，我希望查询也打印他们的 ID 和最大成本。我怎样才能做到这一点？

Answer 1

基本上，您正在寻找应付总额最高的 1 个或多个客户。

WITH customer_total AS
(
SELECT
    CustomerID,
    SUM(TotalDue) as Total
FROM
    "Bike Business".SalesOrderHeader
GROUP BY
    CustomerID
)

SELECT
    CustomerID,
    Total
FROM
    customer_total
WHERE
    Total = (SELECT MAX(Total) FROM customer_total);

Answer 2

在这种情况下，确定子查询中的最大到期金额并将其无限制地加入到您的查询中：

Select CustomerID,Sum(TotalDue) as Total
from "Bike Business"."SalesOrderHeader"
join
    (Select Sum(TotalDue) as MaxTotal
     from "Bike Business"."SalesOrderHeader"
     group by CustomerID
     order by Total desc
     limit 1) t1
group by CustomerID
having Total=t1.MaxTotal

Answer 3

你可以使用子查询

 SELECT CustomerID,su FROM ( 
                SELECT CustomerID,sum(val) as su FROM 
                "Bike Business"."SalesOrderHeader"  GROUP By CustomerID) tmp2 
        WHERE su =(SELECT max(tmp.su) FROM( 
                SELECT CustomerID,sum(val) as su FROM 
                "Bike Business"."SalesOrderHeader"  GROUP By CustomerID)tmp);

Answer 4

您可以为此使用 window 函数：

select "CustomerID", total
from (
  Select "CustomerID",
          Sum("TotalDue") as Total,
          dense_rank() over (order by Sum("TotalDue") desc) as rnk
  from "Bike Business"."SalesOrderHeader" 
  group by "CustomerID"
) t
where rnk = 1;

这可能比使用子select 或派生的 table.

的等效查询更快

而且它还有一个额外的好处，就是您还可以轻松获得第二或第三高的价值。

如果在 Postgres 中平局，我如何显示所有结果？

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