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