SELECT date_of_birth FROM Staff WHERE first_name = "Janessa" AND last_name = "Sawayn";
What is the birthday of the staff member with first name as Janessa and last name as Sawayn?
[Schema (values) (types)]: | driving_school |  Addresses : address_id (text) , line_1_number_building (number) , city (text) , zip_postcode (text) , state_province_county (text) , country (text) | Staff : staff_id (text) , staff_address_id (number) , nickname (text) , first_name (text) , middle_name (text) , last_name (text) , date_of_birth (text) , date_joined_staff (number) , date_left_staff (number) | Vehicles : vehicle_id (text) , vehicle_details (number) | Customers : customer_id (text) , customer_address_id (number) , customer_status_code (text) , date_became_customer (text) , date_of_birth (text) , first_name (text) , last_name (text) , amount_outstanding (number) , email_address (number) , phone_number (text) , cell_mobile_phone_number (text) | Customer_Payments : customer_id (text) , datetime_payment (number) , payment_method_code (text) , amount_payment (text) | Lessons : lesson_id (text) , customer_id (number) , lesson_status_code (text) , staff_id (text) , vehicle_id (text) , lesson_date (text) , lesson_time (text) , price (number);