To quickly recap what you already know about grouping rows in SQL, here is a simple problem: suppose we want to know the average score for each TV show contestant over the course of five weeks. In SQL, we'd write the following query:
SELECT full_name, AVG(score) AS avg_score FROM contest_score GROUP BY full_name;
In this simple query, we grouped the results by a single column (full_name) and used the AVG() function to calculate the average score for each contestant. Nothing really difficult.
How much, in total, was spent on deliveries for each category? Show two columns: category and the sum of total_price (as total).
Simply GROUP BY category.
