Try this problem in the playground
The sample tables will be auto-loaded — write a query and run it instantly.
WHERE vs HAVING
Demonstrate the execution order and difference between WHERE (row filter, before grouping) and HAVING (group filter, after grouping).
Setup & sample data
The playground will create these tables and populate them automatically when you click "Open Playground" above:
Solutions
Multiple approaches — try each and understand the trade-offs.