Skip to main content
Back to problems
#183
Easy Database

Customers who never order

Database
71.5% acceptance
Feb 27, 2026
3038
157
Table: Customers +-------------+---------+ | Column Name | Type | +-------------+---------+ | id | int | | name | varchar | +-------------+---------+ 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. Table: Orders +-------------+------+ | Column Name | Type | +-------------+------+ | id | int | | customerId | int | +-------------+------+ 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.

Solution

SQL
LeetCode
solution.sql
--
-- Table: Customers
-- +-------------+---------+
-- | Column Name | Type    |
-- +-------------+---------+
-- | id          | int     |
-- | name        | varchar |
-- +-------------+---------+
-- 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.
-- Table: Orders
-- +-------------+------+
-- | Column Name | Type |
-- +-------------+------+
-- | id          | int  |
-- | customerId  | int  |
-- +-------------+------+
-- 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:
-- Customers table:
-- +----+-------+
-- | id | name  |
-- +----+-------+
-- | 1  | Joe   |
-- | 2  | Henry |
-- | 3  | Sam   |
-- | 4  | Max   |
-- +----+-------+
-- Orders table:
-- +----+------------+
-- | id | customerId |
-- +----+------------+
-- | 1  | 3          |
-- | 2  | 1          |
-- +----+------------+
-- Output:
-- +-----------+
-- | Customers |
-- +-----------+
-- | Henry     |
-- | Max       |
-- +-----------+
--

# Write your MySQL query statement below

SELECT name AS Customers
FROM Customers
WHERE id NOT IN (SELECT customerId FROM Orders)