Ordering
Eliminating duplicate results
Aggregation
Grouping
HAVING: filtering and ordering groups
Let's practice
Instruction
Correct! There's one more thing before you go. Groups can be sorted just like rows. Take a look:
SELECT customer_id, order_date, SUM(total_sum) FROM orders GROUP BY customer_id, order_date ORDER BY SUM(total_sum) DESC;
In this case, we'll order our rows according to the total daily sum of all orders by a specific customer. The rows with the highest value will appear first.
Exercise
Sort the employees according to their summary salaries. Highest values should appear first. Show the last name, the first name, and the sum.
Stuck? Here's a hint!
Type:
SELECT last_name, first_name, SUM(salary) FROM employees GROUP BY last_name, first_name ORDER BY SUM(salary) DESC;
