Context: CREATE TABLE Lessons (lesson_time INTEGER, customer_id VARCHAR); CREATE TABLE Customers (customer_id VARCHAR, first_name VARCHAR, last_name VARCHAR)
Question: How long is the total lesson time took by customer with first name as Rylan and last name as Goodwin?
Answer: SELECT SUM(T1.lesson_time) 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"