SQL practice: The Big Idea

For every employee, show their name, salary, and the company-wide average salary on every row.

For every employee, show their name, branch, salary, and their own branch's average salary.

For every employee, show how far above or below their branch average they are.

For every product, show its price and the average price of its own category.

For every order item, show the quantity and the total quantity sold of that product across all orders.

For every product, show its price and the highest price in its category.

For every employee, show the number of people in their branch, on every row.

Explain in one sentence why WHERE branch_avg > 60000 fails in 22-2, and how you'd fix it.

List products priced above their category's average. It fails with 'column "cat_avg" does not exist'. Fix it.