TSQL如何做子計算

Question

我有像下面的圖片中的第一個結果的SQL結果，但我想修改它以按照客戶的價格總結，如圖中第二部分所示。付款ID和價格在一張表中，顧客在第二個表中。

這是第一個成果SQL：

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

輸出：

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條款& SUM()聚合函數

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