text: INSERT INTO employee (first_name, last_name, role_id, manager_id)
  VALUES ('Argus', 'Filch', 1, 1),
      ('Rubeus', 'Hagrid', 2, 1),
      ('Albus', 'Dumbledore', 3, 2),
      ('Minerva', 'McGonagall', 4, 1),
      ('Sybill', 'Trelawney', 5, 2),
      ('Filius', 'Flitwick', 6, 2),
      ('Wilhelmina', 'Grubbly-Plank', 7, 2),
      ('Rolanda', 'Hooch', 8, 2),
      ('Gilderoy', 'Lockhart', 9, 2),
      ('Aurora', 'Sinistra', 10, 2),
      ('Severus', 'Snape', 11, 2),
      ('Pomona', 'Sprout', 12, 2);