Customers Who Never Order

Customers Who Never Order

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 |
±----------+

Solution

# Write your MySQL query statement below
SELECT Name AS Customers
  FROM Customers c 
  LEFT JOIN Orders o 
    ON c.Id = o.CustomerId
 WHERE o.Id IS NULL

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转载自blog.csdn.net/byr_wy/article/details/88966037