10.Groups of Combinations

The editor counts customers per country. Split each country into members and non-members.

Show country, is_member and the number of customers in each combination.
How many rows does that result have? Fewer than 9 × 2: a combination with no customers makes no row.
Show customer_id, status and the number of orders, sorted by customer_id and then by status.
Show department_id, title, the number of employees and their total salary.

Something unclear, wrong or missing?

Databaselab-db · PostgreSQL in your browser 0:00

SELECT country, COUNT(*) FROM customers GROUP BY country;

Ctrl↵runs the query · select text to run part of it

Objective 1 of 40/4 done

Customers per country and membership
country, is_member, then the number of customers.