text: DROP DATABASE IF EXISTS staffDB;
  
  CREATE DATABASE staffDB;
  
  USE staffDB;
  
  CREATE TABLE departments (
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id)
  );
  
  CREATE TABLE roles (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL(10, 2),
    department_id INT,
    PRIMARY KEY (id),
    FOREIGN KEY (department_id) REFERENCES departments(id)
  );
  
  CREATE TABLE employees (
    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 roles(id),
    FOREIGN KEY (manager_id) REFERENCES employees(id)
  );
  
  INSERT INTO departments (name)
  VALUES ("department_name_test");
  
  INSERT INTO roles (title, salary, department_id)
  VALUES ("test_role_title", "1000000", 1);
  
  INSERT INTO employees (first_name, last_name, role_id)
  VALUES ("test_first_name", "test_last_name", 1);
  