text: DROP DATABASE IF EXISTS employeetracker_db;
  CREATE database employeetracker_db;
  
  USE employeetracker_db;
  
  CREATE TABLE department (
    id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(30),
    PRIMARY KEY (id)
  );
  
  CREATE TABLE role (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR(30),
    salary DECIMAL(10,2),
    department_id INT NOT NULL,
    PRIMARY KEY (id),
    FOREIGN KEY(department_id) REFERENCES department (id)
  );
  
  CREATE TABLE employee (
    id INT NOT NULL AUTO_INCREMENT,
    first_name VARCHAR(30),
    last_name VARCHAR(30),
    role_id INT NOT NULL,
    manager_id INT, 
    PRIMARY KEY (id),
    FOREIGN KEY (manager_id) REFERENCES employee(id)
    FOREIGN KEY (role_id) REFERENCES role(id)
  );
         
  SELECT * FROM department;
  SELECT * FROM role;
  SELECT * FROM employee;
  