CREATE TABLE student(
  id NUMBER,
  name VARCHAR2(80),
  PRIMARY KEY(id)
);

CREATE TABLE class(
  id NUMBER NOT NULL,
  subject VARCHAR2(80),
  PRIMARY KEY(id)
);

CREATE TABLE class_meeting(
  id NUMBER NOT NULL,
  class_id NUMBER NOT NULL,
  meeting_sequence NUMBER,
  PRIMARY KEY(id),
  foreign KEY(class_id) references class(id)
);

CREATE TABLE meeting_attendance(
  id NUMBER NOT NULL,
  student_id NUMBER NOT NULL,
  meeting_id NUMBER NOT NULL,
  present NUMBER NOT NULL,
  PRIMARY KEY(id),
  foreign KEY(student_id) references student(id),
  foreign KEY(meeting_id) references class_meeting(id),
  CONSTRAINT meeting_attendance_uq UNIQUE(student_id, meeting_id),
  CONSTRAINT present_ck CHECK(present IN(0,1))
);

INSERT INTO student(id, name,)
  VALUES(1, John);
INSERT INTO student(id, name)
  VALUES(2, Mary);
INSERT INTO student(id, name)
  VALUES(3, George);

INSERT INTO class(id, subject)
  (1, 'History');
INSERT INTO class(id, subject)
  (2, 'Math');

INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(1, 1, 1);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(2, 1, 2);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(3, 1, 3);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(4, 2, 1);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(5, 2, 2);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(6, 2, 3);
INSERT INTO class_meeting(id, class_id, meeting_sequence)
  VALUES(7, 2, 4);

INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(1, 1, 1, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(2, 1, 2, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(3, 1, 3, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(4, 1, 4, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(5, 1, 5, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(6, 1, 6, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(7, 1, 7, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(8, 2, 1, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(9, 2, 2, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(10, 2, 3, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(11, 2, 4, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(12, 2, 5, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(13, 2, 6, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(14, 2, 7, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(15, 3, 1, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(16, 3, 2, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(17, 3, 3, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(18, 3, 4, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(19, 3, 5, 0);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(20, 3, 6, 1);
INSERT INTO meeting_attendance(id, student_id, meeting_id, present)
  VALUES(21, 3, 7, 1);

COMMIT;