text: DROP DATABASE IF EXISTS employee_managementDB;
  
  CREATE DATABASE employee_managementDB;
  
  USE employee_managementDB;
  
  CREATE TABLE department (
      id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
      name VARCHAR(25)
  );
  
  CREATE TABLE roles (
      id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
      title VARCHAR(25),
      salary DECIMAL,
      department_id INT,
      FOREIGN KEY (department_id) REFERENCES department(id)
  );
  
  CREATE TABLE employees (
      id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
      first_name VARCHAR(20) NOT NULL,
      last_name VARCHAR(20) NOT NULL,
      role_id INT,
      manager_id INT,
      FOREIGN KEY (role_id) REFERENCES roles(id),
      FOREIGN KEY (manager_id) REFERENCES employees(id)
  );