分析
难度 易
来源
https://leetcode.com/problems/customers-who-never-order/
题目
Suppose that a website contains two tables, the Customers table and the Orders table. Write a SQL query to find all customers who never order anything.
Table: Customers.
+----+-------+
| Id | Name |
+----+-------+
| 1 | Joe |
| 2 | Henry |
| 3 | Sam |
| 4 | Max |
+----+-------+
Table: Orders.
+----+------------+
| Id | CustomerId |
+----+------------+
| 1 | 3 |
| 2 | 1 |
+----+------------+
Using the above tables as example, return the following:
+-----------+
| Customers |
+-----------+
| Henry |
| Max |
+-----------+
解答
Runtime: 220 ms, faster than 94.79% of MySQL online submissions for Customers Who Never Order.
1 # Write your MySQL query statement below 2 3 select Name as Customers from Customers where Id not in (select CustomerId from Orders);