SQL practice: ROW_NUMBER, RANK and DENSE_RANK

Number the products within each category, most expensive first.

Rank all employees by salary, highest first, using RANK().

Rank all employees by salary using DENSE_RANK() and compare with 23-2.

Number each customer's orders from oldest to newest.

Rank branches by how many orders they have.

Rank products within each category by total quantity sold.

Number all employees by salary within their role.

Find the 2nd highest salary in the company using DENSE_RANK() inside a CTE.

Explain when ROW_NUMBER() and RANK() would give different answers on our employees table.

Show the cheapest product in each category. Only one row comes back. Fix it.