ALTER TABLE signed_exams ADD CONSTRAINT signed_exams_student
FOREIGN KEY (PESEL) REFERENCES student (PESEL) ;
ALTER TABLE signed_exams ADD CONSTRAINT signed_exams_p_exam_dates
FOREIGN KEY (exam_time) REFERENCES p_exam_dates (exam_time) ;
ALTER TABLE signed_exams ADD CONSTRAINT signed_exams_examiner
FOREIGN KEY (examiner_id) REFERENCES examiner (id) ;
ALTER TABLE signed_exams ADD CONSTRAINT signed_exams_vehicle
FOREIGN KEY (vehicle_id) REFERENCES vehicle (id) ;
ALTER TABLE signed_exams_t ADD CONSTRAINT signed_exams_t_student
FOREIGN KEY (PESEL) REFERENCES student (PESEL) ;
ALTER TABLE signed_exams_t ADD CONSTRAINT signed_exams_t_t_exam_dates
FOREIGN KEY (exam_time) REFERENCES t_exam_dates (exam_time) ;
ALTER TABLE payment_p ADD CONSTRAINT payment_p_signed_exams
FOREIGN KEY (p_exam_id) REFERENCES signed_exams (id) ;
ALTER TABLE payment_p ADD CONSTRAINT payment_p_student
FOREIGN KEY (PESEL) REFERENCES student (PESEL) ;
ALTER TABLE payment_p ADD CONSTRAINT payment_p_payment_type
FOREIGN KEY (pay_type) REFERENCES payment_type (id) ;
ALTER TABLE payment_t ADD CONSTRAINT payment_p_signed_exams_t
FOREIGN KEY (t_exam_id) REFERENCES signed_exams_t (id) ;
ALTER TABLE payment_t ADD CONSTRAINT payment_t_student
FOREIGN KEY (PESEL) REFERENCES student (PESEL) ;
ALTER TABLE payment_t ADD CONSTRAINT payment_t_payment_type
FOREIGN KEY (pay_type) REFERENCES payment_type (id) ;