text: drop database if exists employeedb;
  create database employeedb;
  use employeedb;
  
  create table department(
  id INTEGER NOT NULL AUTO_INCREMENT primary key,
  name VARCHAR(30)
  );
  
  create table role(
  id INTEGER NOT NULL auto_increment primary key,
  title VARCHAR(30),
  salary decimal(10,2),
  department_id INTEGER NOT NULL,
  foreign key(department_id) references department(id)
  );
  
  create table employee(
  id INTEGER NOT NULL auto_increment primary key,
  first_name VARCHAR(30),
  last_name VARCHAR(30),
  role_id integer,
  manager_id integer,
  foreign key(role_id) references role(id),foreign key(manager_id) references employee(id)
  )
  