Customers Who Never Order SQL Challenge - MySQL Solution

1. Introduction

This blog post discusses a typical SQL query scenario in MySQL: identifying customers from a database who have never placed an order. This kind of query is useful in customer relationship management and sales analysis.

Problem

The challenge is to create a MySQL query that identifies customers who have never made an order from two tables: one containing customer information and the other containing order details.

Database Table:

Customers Table:

Id	Name
1	Alice
2	Bob

Orders Table:

OrderId	CustomerId
100	1

3. MySQL Solution

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

Output:

Name
Bob

Explanation:

1. The query selects names from the Customers table.

2. The WHERE clause uses a subquery to exclude customers who appear in the Orders table.

3. It identifies those customers whose Ids are not present in the list of CustomerIds from the Orders table.

4. This approach efficiently finds customers who have never placed an order.