Instruction
Good job! This query was really challenging!
It's time to wrap things up.
- It's impossible to put a CTE inside another CTE. However, each CTE might use previously defined CTEs in the
FROMclause. - Nested CTEs might be used to compute aggregate functions on a few levels.
- If you need more than just the aggregate result in the outer query, you can use a small subquery.
- CTEs can also be used to compare two (or more) groups of rows.
Are you ready for a short quiz, then?
Exercise
Click to continue.



