SQL Server : How to calculate different sums in a single query

Question

一位 friend 建议我在这里发帖，因为我需要一些帮助!

数据库布局:

**salestable**
salesorder [primary, unique] (sales order number)
salesman (salesperson id)

**salesline**
salesorder [many sales line to single salestable relationship]
saleprice (line amount)
isaccessory (0 or 1)

我想在单个选择中，将销售价格作为每个销售员的总和，但也将销售价格与附件 = 1 相加。

分组和连接不是我所坚持的，而是我是否可以做双重和。

在我的脑海里它看起来像

...salesman,sum(amount) as totalsales,sum(amount where accessory=1) as accessorysales...

但显然那是行不通的!

提前致谢! (PS，我是新来的，温柔点...)

Answer 1

SELECT  salesman, SUM(amount), SUM(CASE WHEN accessory = 1 THEN amount ELSE 0 END)
FROM    salestable t
JOIN    salesorder o
ON      o.salesorder = t.salesorder
GROUP BY
        salesman