Database SQL Question

Question

using https://www.w3schools.com/sql/trysql.asp?filename=trysql_op_in, we want to find the number of products in the table Products (the table has 77 rows) that was sold to the USA customers. No need for duplicates. We use customers-orders-orderdetails-product tables to do so.

Answer 1

select count(distinct p.productid) as "product count"

from customers c

inner join orders o

on c.customerid = o.customerid

inner join orderdetails od

on o.orderid = od.orderid

inner join products p

on od.productid = p.productid

where c.country = 'USA'