text: DROP DATABASE IF EXISTS employee_db;
  CREATE DATABASE employee_db;
  USE employee_db;
  
  -- Generate the departments table with id and name columns
  CREATE TABLE departments(
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id)
  );
  
  -- Generate the roles table with id, title, salary, department_id columns
  CREATE TABLE roles(
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL NOT NULL,
    department_id INT,
    PRIMARY KEY (id),
    FOREIGN KEY (department_id) REFERENCES departments(id)
  );
  
  -- Generate the employees table with id, first name, last name, role id, manager id columns
  CREATE TABLE employees(
    id INT AUTO_INCREMENT,
    first_name VARCHAR(30),
    last_name VARCHAR(30),
    role_id INT REFERENCES roles.id,
    manager_id INT REFERENCES employee.id,
    PRIMARY KEY (id)
  );