Try this problem in the playground
The sample tables will be auto-loaded — write a query and run it instantly.
Window functions — ROW_NUMBER, RANK, DENSE_RANK
Show three ways to rank employees by salary within each department. Notice how they behave differently when there are ties.
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.