183 - 从不订购的客户
题目描述
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 |
+-----------+
链接:https://leetcode-cn.com/problems/customers-who-never-order
题解
# Write your MySQL query statement below
SELECT Name Customers
FROM Customers
WHERE Id NOT IN
(SELECT CustomerId
FROM Orders);