从不订购的客户
难度简单369收藏分享切换为英文接收动态反馈
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 );