text: DROP DATABASE IF EXISTS hrDB;
  
  CREATE DATABASE hrDB;
  
  USE hrDB;
  
  CREATE TABLE department (
      id INT PRIMARY KEY AUTO_INCREMENT,
      name VARCHAR(100) NULL
  );
  
  CREATE TABLE role (
      id INT PRIMARY KEY AUTO_INCREMENT,
      title VARCHAR(30),
      salary DECIMAL,
      department_id INT,
      FOREIGN KEY (department_id) REFERENCES department(id)
  
  );
  
  CREATE TABLE employee (
      id INT PRIMARY KEY AUTO_INCREMENT,
      first_name VARCHAR(30),
      last_name VARCHAR(30),
      role_id INT,
      manager_id INT,
      FOREIGN KEY (role_id) REFERENCES role(id),
      FOREIGN KEY (manager_id) REFERENCES employee(id)
  );
  
  INSERT INTO department(name)
  VALUES("Management"),
      ("Sales"),
      ("Labor");
  
  INSERT INTO role(title, salary, department_id)
  VALUES("Manager", 80000, 1),
      ("Salesperson", 60000,2),
      ("Labor", 40000,3);
   
  INSERT INTO employee(first_name,last_name,role_id,manager_id)
  
  VALUES("Big", "Boss", 1, NULL),
      ("James", "Fast-Money", 2, 1),
      ("Peter", "ABC",2,1),
      ("Small","Boss",1,NULL),
      ("Poor","Guy",3,4),
      ("Tired", "Dude", 3, 4);