First, we define two database tables that don't have any foreign keys:
--
-- salespeople
--
CREATE TABLE salespeople (
id INTEGER PRIMARY KEY,
first_name TEXT NOT NULL,
last_name TEXT NOT NULL,
commission_rate REAL NOT NULL
);
--
-- customers
--
CREATE TABLE customers (
id INTEGER PRIMARY KEY,
company_name TEXT NOT NULL,
street_address TEXT NOT NULL,
city T...
