text: DROP DATABASE IF EXISTS employee_tracker_db;
  CREATE DATABASE employee_tracker_db;
  USE employee_tracker_db;
  
  CREATE TABLE department (
  	id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,  
      dept_name VARCHAR(30) 
      );
      
  CREATE TABLE role (
  	id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,     
      title VARCHAR(30),     
      salary DECIMAL,     
      department_id INT,     
      FOREIGN KEY(department_id) 
      REFERENCES department(id) 
      ON DELETE CASCADE 
      );
      
  CREATE TABLE employee ( 
  	id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, 
      first_name VARCHAR(30) NOT NULL, 
      last_name VARCHAR(30) NOT NULL, 
      role_id INT NOT NULL, 
      manager_id INT, 
      FOREIGN KEY(role_id) 
      REFERENCES role(id) 
      ON DELETE CASCADE, 
      FOREIGN KEY(manager_id) 
      REFERENCES employee(id) 
      ON DELETE CASCADE 
      );
  