SQL practice: LEFT JOIN: Keep Everything On The Left

Find branches that have never had an order.

List every customer with their order count, including the ones with zero.

List every branch with how many employees it has, including any with none.

Find products that have never been sold.

List every product with the total quantity sold, showing 0 for the unsold ones.

List every branch with its total revenue, showing 0 where there is none.

List every employee and the number of orders they handled, including those who handled none.

Explain why COUNT(*) gives the wrong answer in 13-2, and what it would show instead.

List every customer with their count of Delivered orders only, still including customers with none. (Careful where you put the condition.)

A report counting customers uses COUNT(*) after a LEFT JOIN to orders, and says every customer has at least one order. Why?

List every customer with how many Delivered orders they have. Customers with none should show 0, but they vanish. Fix it.