text: DROP DATABASE IF EXISTS employees_db;
  CREATE DATABASE employees_db;
  
  USE employees_db;
  
  CREATE TABLE department(
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id)
  );
  
  CREATE TABLE role (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL(65,2) NOT NULL,
    department_id INT,
    PRIMARY KEY (id),
    FOREIGN KEY (department_id) REFERENCES department(id)
  );
  
  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),
    FOREIGN KEY (role_id) REFERENCES role(id)
  );