create table appointments
(
    id    bigint not null auto_increment,
    doctor_id bigint not null,
    patient_id bigint not null,
    date datetime not null,

    primary key (id),
    constraint fk_appointments_doctor_id foreign key(doctor_id) references doctors(id),
    constraint fk_appointments_patient_id foreign key(patient_id) references patients(id)

);