Oracle SQL获取商店分支和产品类别，分支销售额最大[重复]

Question

我有一个具有多个分支的商店的架构。我正在尝试获取分支机构列表及其最畅销的产品类别。

ERD design for the tables

这是我从查询中得到的：

select branch_name,prod_category,sum(p.prod_price*il.inv_line_qty) as 
Category_Value
from w_branches b
 inner join w_products p on p.branch_id= b.branch_id
 inner join w_inv_line il on il.prod_id= p.prod_id
 inner join w_invoices i on i.inv_id=il.inv_id
group by p.branch_id, b.branch_name,p.prod_category;

这将返回一个分支名称列表，其中包含该分支拥有的每个产品类别以及该类别的总销售额。

BRANCH_NAME      PRODUCT CATEGORY        TOTAL SALES
---------------- ------------------------------------
BRANCHMALL       CPU                     41808
BRANCH_POS       Desktop                 62282
BRANCH_EAST      CPU                     51510
BRANCH_EAST      Networking              81600
BRANCH_POS       CPU                     22477
BRANCH_CENTRAL   Desktop                 126066
BRANCHMALL       SSD                     93154
BRANCH_NORTH     CPU                     217685

如您所见，分支正在重复。我只想获取分店销售额最高的类别，如下所示。

BRANCH_NAME      PRODUCT CATEGORY        TOTAL SALES
---------------- ------------------------------------
BRANCH_POS       Desktop                 62282
BRANCH_EAST      Networking              81600
BRANCH_CENTRAL   Desktop                 126066
BRANCHMALL       SSD                     93154
BRANCH_NORTH     CPU                     217685

谢谢！

Answer 1

为此，您可以在 oracle 中使用 rank() 来识别排名，然后选择具有一个排名的所有值。

select * from (
select branch_name, prod_category,category_value, rank() over (partition by branch_name order by category_value desc) as rank from
(select branch_name,prod_category,sum(p.prod_price*il.inv_line_qty) as 
Category_Value
from w_branches b
 inner join w_products p on p.branch_id= b.branch_id
 inner join w_inv_line il on il.prod_id= p.prod_id
 inner join w_invoices i on i.inv_id=il.inv_id
group by p.branch_id, b.branch_name,p.prod_category))
where rank = 1)