text: --Drop DB if exists and recreate clean version and use it.
  CREATE DATABASE employees;
  DROP DATABASE IF EXISTS employees;
  USE employees;
  
  -- Create Employee Table
  Create TABLE department (
      id INT AUTO_INCREMENT PRIMARY KEY,
      name VARCHAR(50) UNIQUE NOT NULL
  );
  
  
  --Table Role
  Create Table Role (
      id INT AUTO_INCREMENT PRIMARY KEY,
      title VARCHAR(50) UNIQUE NOT NULL,
      salary DECIMAL NOT NULL,
      department_id INT NOT NULL,
      CONSTRAINT fk_department FOREIGN KEY (department_id) References department(id) on delete cascade
  
  );
  
  --Create Employee Table
  CREATE TABLE EMPLOYEE (
      id INT AUTO_INCREMENT PRIMARY KEY,
      first_name VARCHAR(50) UNIQUE NOT NULL,
      last_name VARCHAR(50) NOT NULL,
      role_id INT NOT NULL,
      manager_id INT,
      CONSTRAINT fk_manager FOREIGN KEY (manager_id) References employee(id) on delete set null
  );