text: INSERT INTO country (name) VALUES ('Russian Federation'), ('Ukraine'), ('Australia');
  
  INSERT INTO city (name, country_id)
  VALUES ('Moscow', (SELECT id FROM country WHERE name='Russian Federation')),
         ('Saint Petersburg', (SELECT id FROM country WHERE name='Russian Federation')),
         ('Kiev', (SELECT id FROM country WHERE name='Ukraine')),
         ('Sydney', (SELECT id FROM country WHERE name='Australia'));
  
  UPDATE users SET city_id = (SELECT c.id FROM city c WHERE name='Moscow')