码迷,mamicode.com
首页 > 其他好文 > 详细

183. Customers Who Never Order--solution

时间:2018-03-03 18:20:26      阅读:146      评论:0      收藏:0      [点我收藏+]

标签:table   body   join   pos   sel   turn   null   example   win   

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

标签:table   body   join   pos   sel   turn   null   example   win   

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

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!