text: -- Create a DB with 3 tables
  DROP DATABASE IF EXISTS ems_db;
  
  CREATE DATABASE ems_db;
  
  USE ems_db;
  
  
  CREATE TABLE department (
    id INT NOT NULL AUTO_INCREMENT,
    dept_name VARCHAR(30) NOT NULL,
    PRIMARY KEY (id) 
  );
  
  CREATE TABLE empRole (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30),
    salary DECIMAL(10),
    dept_id INT,
    PRIMARY KEY (id),
    FOREIGN KEY (dept_id) REFERENCES department(id)
  );
  
  CREATE TABLE employee (
  	id INT NOT NULL AUTO_INCREMENT,
      firstname VARCHAR(30),
      surname VARCHAR(30),
      role_id INT NOT NULL,
      manager_id INT,
      manager BOOLEAN, 
      PRIMARY KEY (id),
      FOREIGN KEY (role_id) REFERENCES empRole(id),
      FOREIGN KEY (manager_id) REFERENCES employee(id)
  );
  
  
  
  
  -- ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'rootroot'