text: DROP DATABASE IF EXISTS employee_trackerDB;
  CREATE DATABASE employee_trackerDB;
  USE employee_trackerDB;
  CREATE TABLE department (
    id INT PRIMARY KEY UNIQUE,
    name VARCHAR(30)
  );
  CREATE TABLE role (
    id INT PRIMARY KEY UNIQUE,
    title VARCHAR(30),
    salary DECIMAL(10, 2),
    department_id INT
  );
  CREATE TABLE employee (
    id INT PRIMARY KEY UNIQUE,
    first_name VARCHAR(30),
    last_name VARCHAR(30),
    role_id INT,
    manager_id INT
  );