从不订购的客户(C++)

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从不订购的客户

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SQL架构

某网站包含两个表,Customers 表和 Orders 表。编写一个 SQL 查询,找出所有从不订购任何东西的客户。

Customers 表:

+----+-------+
| Id | Name  |
+----+-------+
| 1  | Joe   |
| 2  | Henry |
| 3  | Sam   |
| 4  | Max   |
+----+-------+

Orders 表:

+----+------------+
| Id | CustomerId |
+----+------------+
| 1  | 3          |
| 2  | 1          |
+----+------------+

例如给定上述表格,你的查询应返回:

+-----------+
| Customers |
+-----------+
| Henry     |
| Max       |
+-----------+

我的代码:

# Write your MySQL query statement below
select customers.name as "Customers"
from customers
where customers.id not in
(
    select customerid from orders
);