LeetCode 0183 - Customers Who Never Order

Customers Who Never Order

Desicription

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.

代码语言：javascript复制

 ---- ------- 
| Id | Name  |
 ---- ------- 
| 1  | Joe   |
| 2  | Henry |
| 3  | Sam   |
| 4  | Max   |
 ---- ------- 

Table: Orders.

代码语言：javascript复制

 ---- ------------ 
| Id | CustomerId |
 ---- ------------ 
| 1  | 3          |
| 2  | 1          |
 ---- ------------ 

Using the above tables as example, return the following:

代码语言：javascript复制

 ----------- 
| Customers |
 ----------- 
| Henry     |
| Max       |
 ----------- 

Solution

代码语言：javascript复制

SELECT Name
AS Customers
FROM Customers
WHERE Id NOT IN
(SELECT CustomerId FROM Orders)

sql orders return table using

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