text: DROP DATABASE IF EXISTS personnel_managerDB;
  CREATE DATABASE personnel_managerDB;
  USE personnel_managerDB;
  ALTER USER'root'@'localhost' IDENTIFIED BY 'password';
  CREATE TABLE department(
   id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
   name VARCHAR(30) NOT NULL
  );
  CREATE TABLE role(
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  title VARCHAR(30) NOT NULL,
  salary DECIMAL NOT NULL,
  department_id INT NOT NULL,
  FOREIGN KEY (department_id) REFERENCES department(id)
  );
  CREATE TABLE employee(
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  first_name VARCHAR(30) NOT NULL,
  last_name VARCHAR(30) NOT NULL,
  role_id INT NOT NULL,
  manager_id INT,
  FOREIGN KEY (role_id) REFERENCES role(id),
  FOREIGN KEY (manager_id) REFERENCES employee(id)
  )