text: DROP DATABASE IF EXISTS employee_manager_db;
  
  CREATE DATABASE employee_manager_db;
  
  USE employee_manager_db;
  
  CREATE TABLE department (
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id)
  );
  
  SELECT * FROM department;
  SELECT department.name FROM department;
  
  CREATE TABLE role (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL NOT NULL,
    department_id INT NOT NULL,
    PRIMARY KEY (id),
    FOREIGN KEY (department_id) REFERENCES department(id)
  );
  
  SELECT * FROM role;
  
  CREATE TABLE employee (
    id INT NOT NULL AUTO_INCREMENT,
    first_name VARCHAR(30) NOT NULL,
    last_name VARCHAR(30) NOT NULL,
    role_id INT NOT NULL,
    manager_id INT,
    PRIMARY KEY (id),
    FOREIGN KEY (role_id) REFERENCES role(id),
    FOREIGN KEY (manager_id) REFERENCES employee(id)
  );
  
  SELECT * FROM employee;
      
  -- template used to test queries before adding to the JS file
  SELECT 
  	   employee.id AS "ID"
       , CONCAT(employee.first_name, ' ', employee.last_name) AS "Employee"
       , role.title AS "Title"
       , department.name AS "Department"
       , role.salary AS "Salary"
  	 , CONCAT(B.first_name, ' ', B.last_name) AS "Manager"
    FROM employee 
    LEFT JOIN role
  		ON employee.role_id = role.id
    LEFT JOIN department
  		ON role.department_id = department.id
    LEFT JOIN employee B
  		ON employee.manager_id = B.id
   WHERE department.name = "Sales";