Instruction
Excellent! Now let's see how we can show the revenue generated by various groups to date. For instance:
SELECT c.customer_id, c.company_name, SUM(o.amount) AS total_revenue FROM orders o JOIN customers c ON o.customer_id = c.customer_id GROUP BY c.customer_id, c.company_name;
The query above shows the revenue to date for each customer. To find the total amount for each customer, we group the whole query by the customer_id and company_name columns from the customers table.
Exercise
Show each category_id and category_name alongside the total_revenue generated by all order items from that category.
Stuck? Here's a hint!
Join the order_items and products and categories tables. Group by category_id and category_name.



