text: DROP DATABASE IF EXISTS employeeDB;
  CREATE database employeeDB;
  USE employeeDB;
  
  CREATE TABLE department (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(30) NOT NULL
  );
  CREATE TABLE role (
  id INT 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) ON DELETE CASCADE
  );
  CREATE TABLE employee (
  id INT 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) ON DELETE CASCADE,
  FOREIGN KEY(manager_id)REFERENCES employee(id) ON DELETE SET NULL
  );
  
  
  
  
  