GROUP BY in SQL
SQL interview exercise on Aggregation, difficulty 1 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
For each product category return how many products it has and their average price, rounded to 2 decimals. Columns: category, products, avg_price. Sorted by category.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.