262 CHAPTER 15: HIERARCHICAL DATABASE SYSTEMS (IMS) dept_id CHAR(7) NOT NULL REFERENCES Departments (dept_id) ON UPDATE CASCADE) ; CREATE TABLE Students (student_id CHAR(9) NOT NULL PRIMARY KEY, student_name CHAR(35) NOT NULL, address CHAR(35) NOT NULL, major CHAR(10)); CREATE TABLE Departments (dept_id CHAR(7) NOT NULL PRIMARY KEY, dept_name CHAR(15) NOT NULL, chairman_name CHAR(35) NOT NULL, budget_code CHAR(3) NOT NULL); 15.3.1 Department Database Segments in the Department database are as follow.