难度:Easy
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 |+-----------+
需要注意Orders表中的去重,
# Write your MySQL query statement belowSELECT Name as Customers from Customers WHERE Id NOT IN (SELECT DISTINCT CustomerId from Orders)