can you show me a list of lesson date?
select lesson_date from lessons
what is the average of lesson time?
select avg ( lesson_time ) from lessons
what is the highest price?
select price from lessons order by price desc limit 1
how many lessons does customer with first name ray took?
select count ( * ) from lessons as t1 join customers as t2 on t1.customer_id = t2.customer_id where t2.first_name = "Ray"