Ranking functions
ROW_NUMBER, RANK, DENSE_RANK, NTILE, and the top-N-per-group pattern.
We mark it against a checklist you can read first
What counts as knowing this
Return the top N rows per group with the right tie-breaking behaviour
A check for this one skill
Up to 1 question on this skill alone, marked against the bar beside this. It stops as soon as the answer is clear. No account, and your answers are not kept.
You'll need these first
Helpful, but not required
What it unlocks
Start on SQL & Data Analysis
Every skill above, ordered by what depends on what, with the projects above that as the evidence you actually did it. We work out where you already are first, so the path skips what you can do.
Start this path