text: DROP DATABASE IF EXISTS business_db;
  
  CREATE DATABASE business_db;
  
  USE business_db;
  
  CREATE TABLE department (
  	id INTEGER AUTO_INCREMENT NOT NULL,
      name VARCHAR(30) NOT NULL,
      PRIMARY KEY (id)
  );
  
  CREATE TABLE role (
  	id INTEGER AUTO_INCREMENT NOT NULL,
      title VARCHAR(30) NOT NULL,
      salary DECIMAL(10,2),
      department_id INT(10) NOT NULL,
  	
      PRIMARY KEY (id),
      FOREIGN KEY (department_id) REFERENCES deparment(id)
  );
  
  CREATE TABLE employee (
  	id INTEGER AUTO_INCREMENT NOT NULL,
      first_name VARCHAR(30) NOT NULL,
      last_name VARCHAR(30) NOT NULL,
      role_id INT(10) NOT NULL,
      manager_id INT(10),
      department_id INT(10) NOT NULL,
      
      PRIMARY KEY (id),
      FOREIGN KEY (department_id) REFERENCES department(id)
      
      );
  