mysql left join

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

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/customers-who-never-order
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

SELECT NAME Customers 
FROM customers A
LEFT JOIN Orders  B
ON A.id = B.CustomerId
WHERE B.id IS NULL

Customers表

create table `customers` (
	`id` int (11),
	`Name` varchar (60)
); 
insert into `customers` (`id`, `Name`) values('1','Joe');
insert into `customers` (`id`, `Name`) values('2','Henry');
insert into `customers` (`id`, `Name`) values('3','Sam');
insert into `customers` (`id`, `Name`) values('4','Max   ');

Orders表

create table `orders` (
	`Id` int (11),
	`CustomerId` varchar (60)
); 
insert into `orders` (`Id`, `CustomerId`) values('1','3');
insert into `orders` (`Id`, `CustomerId`) values('2','1');