text: DROP DATABASE IF EXISTS  tracker_db;
  
  CREATE DATABASE tracker_db;
  
  USE  tracker_db;
  
  CREATE TABLE department (
      id INT NOT NULL AUTO_INCREMENT,
      name VARCHAR (30) NOT NULL,
      PRIMARY KEY (id)
  
  );
  CREATE TABLE role (
      id INT(10) NOT NULL AUTO_INCREMENT,
      title VARCHAR(30) NOT NULL,
      salary DECIMAL(10, 2) NOT NULL,
      department_id INT(10) NOT NULL,
      PRIMARY key (id)
  );
  CREATE TABLE employee (
      id INT(10) NOT NULL AUTO_INCREMENT,
      first_name VARCHAR(30) NOT NULL,
      last_name VARCHAR(30) NOT NULL,
      role_id INT(10) NOT NULL,
      manager_id INT(10),
      PRIMARY KEY (id)
  )
  
  