Last updated on October 10th, 2024 at 12:10 am

This Leetcode problem Customers Who Never Order LeetCode Solution is done in SQL.

List of all LeetCode Solution

Customers Who Never Order LeetCode Solution

Problem Statement

id is the primary key (column with unique values) for this table. Each row of this table indicates the ID and name of a customer.

id is the primary key (column with unique values) for this table. customerId is a foreign key (reference columns) of the ID from the Customers table. Each row of this table indicates the ID of an order and the ID of the customer who ordered it.

Write a solution to find all customers who never order anything.

Return the result table in any order.

The result format is in the following example.

Example 1:
Input:

Output:

1. Customers Who Never Order LeetCode Solution MySQL

select 
  Name as Customers 
from 
  Customers 
where 
  Id not in (
    select 
      CustomerId 
    from 
      Orders
  );