首页 > 其他 > 详细

183. Customers Who Never Order--solution

时间:2018-03-03 17:48:12      阅读:231      评论:0      收藏:0      [点我收藏+]

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       |
+-----------+


My solution:

SELECT A.Name as Customers from Customers A
LEFT JOIN Orders B on A.Id = B.CustomerId
WHERE B.CustomerId is NULL;

183. Customers Who Never Order--solution

原文:https://www.cnblogs.com/chenwong/p/8497062.html

(0)
(0)
   
举报
评论 一句话评论(0
关于我们 - 联系我们 - 留言反馈 - 联系我们:wmxa8@hotmail.com
© 2014 bubuko.com 版权所有
打开技术之扣,分享程序人生!