TSQL如何做子计算

Question

我有像下面的图片中的第一个结果的SQL结果，但我想修改它以按照客户的价格总结，如图中第二部分所示。付款ID和价格在一张表中，顾客在第二个表中。

这是第一个成果SQL：

select 
    p.payment_id, p.price, c.customer 
from 
    payments p 
left join 
    customers c on p.payment_id = c.payment_id 

输出：

Answer 1

SELECT SUM (p.price) price, c.customer 
    FROM payments p LEFT JOIN customers c on p.payment_id = c.payment_id 
GROUP BY c.customer 

Answer 2

select sum(p.price) as price, c.customer 
from payments p 
left join customers c 
on p.payment_id = c.payment_id 
group by c.customer 
order by c.customer 

Answer 3

使用GROUP BY条款& SUM()聚合函数

select SUM(p.price) AS price, c.customer 
from payments p 
left join customers c 
    on p.payment_id = c.payment_id 
group by c.customer