text: DROP DATABASE IF EXISTS tracker_DB;
  CREATE DATABASE tracker_DB;
  
  USE tracker_DB;
  
  CREATE TABLE department(
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id)
  );
  
  
  CREATE TABLE roles(
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL(10,4) NOT NULL,
    department_id INT NOT NULL, 
    PRIMARY KEY (id)
  );
  
  CREATE TABLE employees(
    id INT NOT NULL AUTO_INCREMENT,
    first_name VARCHAR(30) NOT NULL,
    last_name VARCHAR(30) NOT NULL,
    role_id INT NOT NULL,
    PRIMARY KEY (id)
  );
  
  