183. 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 c2.Name as Customers
from Customers c2
where c2.Id 
not in 
(select o.CustomerId
from Customers c, Orders o
where c.Id = o.CustomerId)