Если добавить несколько JOIN, то таблица выводится пустой

SELECT booking.id, employee.surname, time_slot.time_slot, booking.visitor_name, booking.visitor_email, booking.visitor_ph, services.name, booking.book_date FROM booking
JOIN employee ON booking.id_employee = employee.id_employee
JOIN time_slot ON booking.id_time_slot = time_slot.time_slot
JOIN services ON booking.id_services = services.name

Если писать 1 JOIN, то всё выводится хорошо

SELECT booking.id, employee.surname,  booking.visitor_name, booking.visitor_email, booking.visitor_ph, booking.book_date FROM booking
JOIN employee ON booking.id_employee = employee.id_employee