MySQL — Right Join

Basic RIGHT JOIN

SELECT * FROM users
RIGHT JOIN orders ON users.id = orders.user_id;

RIGHT JOIN Examples

-- All orders with user info
SELECT
    u.name,
    o.total,
    o.created_at
FROM users u
RIGHT JOIN orders o ON u.id = o.user_id;

-- Orders without valid users
SELECT o.*
FROM users u
RIGHT JOIN orders o ON u.id = o.user_id
WHERE u.id IS NULL;

-- All products, even not ordered
SELECT
    p.name,
    COALESCE(SUM(oi.quantity), 0) as total_sold
FROM products p
RIGHT JOIN order_items oi ON p.id = oi.product_id
GROUP BY p.id;

RIGHT JOIN vs LEFT JOIN

-- RIGHT JOIN
SELECT * FROM users
RIGHT JOIN orders ON users.id = orders.user_id;

-- Equivalent LEFT JOIN (reversed tables)
SELECT * FROM orders
LEFT JOIN users ON orders.user_id = users.id;

Mini Practice

Write MySQL code that:

1. Uses RIGHT JOIN
2. Finds unmatched records
3. Compares with LEFT JOIN
4. Uses RIGHT JOIN with aggregates

Up Next

Next: Learn about Cross Join.