CREATE TABLE staff (staff_id NUMBER, staff_address_id NUMBER, nickname CLOB, first_name CLOB, middle_name CLOB, last_name CLOB, date_of_birth TIME, date_joined_staff TIME, date_left_staff TIME)
CREATE TABLE addresses (address_id NUMBER, line_1_number_building CLOB, city CLOB, zip_postcode CLOB, state_province_county CLOB, country CLOB)
CREATE TABLE customers (customer_id NUMBER, customer_address_id NUMBER, customer_status_code CLOB, date_became_customer TIME, date_of_birth TIME, first_name CLOB, last_name CLOB, amount_outstanding NUMBER, email_address CLOB, phone_number CLOB, cell_mobile_phone_number CLOB)
CREATE TABLE vehicles (vehicle_id NUMBER, vehicle_details CLOB)
CREATE TABLE customer_payments (customer_id NUMBER, datetime_payment TIME, payment_method_code CLOB, amount_payment NUMBER)
CREATE TABLE lessons (lesson_id NUMBER, customer_id NUMBER, lesson_status_code CLOB, staff_id NUMBER, vehicle_id NUMBER, lesson_date TIME, lesson_time CLOB, price NUMBER)

What is average lesson price taught by staff with first name as Janessa and last name as Sawayn?
SELECT AVG(price) FROM lessons AS T1 JOIN staff AS T2 ON T1.staff_id = T2.staff_id WHERE T2.first_name = "Janessa" AND T2.last_name = "Sawayn"
SELECT AVG("price") FROM "lessons" "T1" JOIN "staff" "T2" ON "Janessa" = "T2"."first_name" AND "Sawayn" = "T2"."last_name" AND "T1"."staff_id" = "T2"."staff_id"