CREATE TABLE class ( class_id INT, class_name VARCHAR(100), CONSTRAINT class_id_pk PRIMARY KEY (class_id) ); CREATE TABLE lecture ( lecture_id INT, class_id INT, lecture_dt DATE, CONSTRAINT lecture_id_pk PRIMARY KEY (lecture_id), CONSTRAINT lecture_class_id_fk FOREIGN KEY (class_id) REFERENCES class (class_id) ); CREATE TABLE student ( student_id INT, student_first_name VARCHAR(20), student_last_name VARCHAR(20), CONSTRAINT student_id_pk PRIMARY KEY (student_id) ); CREATE TABLE attendance ( lecture_id INT, student_id INT, attendance_present INT CHECK (attendance_present in (0,1)), CONSTRAINT attendance_pk PRIMARY KEY (lecture_id, student_id), CONSTRAINT att_lecture_id_fk FOREIGN KEY (lecture_id) REFERENCES lecture (lecture_id), CONSTRAINT att_student_id_fk FOREIGN KEY (student_id) REFERENCES student (student_id) );