Context: CREATE TABLE Lessons (customer_id VARCHAR, lesson_status_code VARCHAR); CREATE TABLE Customers (customer_id VARCHAR, first_name VARCHAR, last_name VARCHAR)
Question: How many lessons taken by customer with first name as Rylan and last name as Goodwin were completed?
Answer: SELECT COUNT(*) FROM Lessons AS T1 JOIN Customers AS T2 ON T1.customer_id = T2.customer_id WHERE T2.first_name = "Rylan" AND T2.last_name = "Goodwin" AND T1.lesson_status_code = "Completed"