CREATE TABLE customer (first_name VARCHAR(255), customer_id VARCHAR(255), rental_date INTEGER); CREATE TABLE rental (first_name VARCHAR(255), customer_id VARCHAR(255), rental_date INTEGER)
What are the first names of customers who have not rented any films after '2005-08-23 02:06:01'?
    
SQL: SELECT first_name FROM customer WHERE NOT customer_id IN (SELECT customer_id FROM rental WHERE rental_date > '2005-08-23 02:06:01')