Summary - LEFT and RIGHT JOIN

Write a missing-record report with LEFT JOIN.

LEFT JOIN keeps all rows of the left table, RIGHT JOIN keeps all rows of the right table. The unmatched side becomes NULL.

SELECT c.name, o.id
FROM customers c
LEFT JOIN orders o ON o.customer_id = c.id;

Summary left join.

c.name, o.id is selected from customers c. orders o is joined on o.customer_id = c.id, keeping every row of the left table.

Exercise Summary - LEFT and RIGHT JOIN

Summary: LEFT JOIN customers with orders.

Show example solution

SELECT c.name, o.id
FROM customers c
LEFT JOIN orders o ON o.customer_id = c.id;