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 |+-----------+
My solution:
SELECT A.Name as Customers from Customers A
LEFT JOIN Orders B on A.Id = B.CustomerIdWHERE B.CustomerId is NULL;