How do I use JOIN in SQL to combine data from multiple tables?

How do I use JOIN in SQL to combine data from multiple tables?

You can use the JOIN clause in SQL to combine rows from two or more tables based on a related column. For example, you can use INNER JOIN, LEFT JOIN, RIGHT JOIN, or FULL JOIN depending on your needs.

Can you give me an example of an INNER JOIN?

Sure! If you have a 'customers' table and an 'orders' table, you can use INNER JOIN like this: SELECT customers.name, orders.amount FROM customers INNER JOIN orders ON customers.id = orders.customer_id; This will return names of customers along with their order amounts.

What if I want to include customers who haven't placed any orders?

In that case, you would use a LEFT JOIN. It will return all customers and their orders, but if a customer has no orders, the order fields will be NULL.

Can you show me the SQL for that?

Absolutely! The SQL would look like this: SELECT customers.name, orders.amount FROM customers LEFT JOIN orders ON customers.id = orders.customer_id; This will include all customers, even those without orders.