text: DROP DATABASE IF EXISTS employee_db;
  CREATE DATABASE employee_db;
  USE employee_db;
  
  CREATE TABLE department(
  id INT AUTO_INCREMENT NOT NULL,
  name VARCHAR(30) NOT NULL,
  PRIMARY KEY (id)
  );
  TRUNCATE department;
  INSERT INTO department(name) VALUES ("General Management");
  INSERT INTO department(name) VALUES ("Sales");
  INSERT INTO department(name) VALUES ("Human Resources");
  INSERT INTO department(name) VALUES ("Engineering");
  INSERT INTO department(name) VALUES ("Legal");
  
  CREATE TABLE role(
  id INT AUTO_INCREMENT NOT NULL,
  title VARCHAR(30) NOT NULL,
  salary DECIMAL(10,2) NOT NULL,
  department_id INT NOT NULL,
  PRIMARY KEY (id)
  );
  
  TRUNCATE role;
  INSERT INTO role(title, salary, department_id) VALUES ("General Manager", 100000, 1);
  INSERT INTO role(title, salary, department_id) VALUES ("Assistant Manager", 80000, 1);
  INSERT INTO role(title, salary, department_id) VALUES ("Sales Lead", 50000, 2);
  INSERT INTO role(title, salary, department_id) VALUES ("Salesperson", 40000, 2);
  INSERT INTO role(title, salary, department_id) VALUES ("HR Specialist", 60000, 3);
  INSERT INTO role(title, salary, department_id) VALUES ("Recruiter", 50000, 3);
  INSERT INTO role(title, salary, department_id) VALUES ("Software Engineer", 100000, 4);
  INSERT INTO role(title, salary, department_id) VALUES ("Lawyer", 125000, 5);
  
  CREATE TABLE employee(
  id INT AUTO_INCREMENT NOT NULL,
  first_name VARCHAR(30) NOT NULL,
  last_name VARCHAR(30) NOT NULL,
  role_id INT NOT NULL,
  manager_id INT,
  PRIMARY KEY (id)
  );
  
  TRUNCATE employee;
  INSERT INTO employee(first_name, last_name, role_id) VALUES ("Andrew", "Bautista", 1);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Michelle", "Rojas", 2, 1);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Amy", "Martins", 5, 1);
  INSERT INTO employee(first_name, last_name, role_id) VALUES ("Alyssa", "Pepe", 8);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Scarlett", "Rosalie", 3, 2);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Barbara", "Soto", 7, 2);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Charles", "Casseus", 4, 5);
  INSERT INTO employee(first_name, last_name, role_id, manager_id) VALUES ("Thomas", "Pepe", 6, 3);
  
  SELECT * FROM employee;
  SELECT * FROM role;
  SELECT * FROM department;
  
  SELECT CONCAT(first_name, ' ', last_name) as employees FROM employee where manager_id=1