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