The Busiest Months

The last slide is about the busiest months: the months in which customers placed at least 3 paid orders. The refunded orders don't count. Show each such month in the form 2024-12 as month, the number of its paid orders as paid_orders, and how many different customers placed them as customers, sorted by month:

In both months, three different customers placed the three orders, but the two numbers aren't always the same: a customer can place several orders in one month.

A tip: some conditions are about a single order, and others about a whole month. Remember from the lesson on grouping where each of them goes.

That's the whole project. You've summed up the shop in three queries: they group rows by calculated values, count and average them, and keep only the groups that matter. Each of them, though, has used a single table. In the next lesson, you'll learn to join tables, so that one query can show, for example, the names of the customers next to their orders.