ALTER TABLE users
  ADD COLUMN invite_par_id INT UNSIGNED DEFAULT NULL AFTER site_web,
  ADD COLUMN date_postulation DATE DEFAULT NULL AFTER invite_par_id,
  ADD COLUMN reception_connu TINYINT(1) NOT NULL DEFAULT 0 AFTER date_postulation,
  ADD COLUMN reception_inconnu TINYINT(1) NOT NULL DEFAULT 0 AFTER reception_connu,
  ADD COLUMN date_entretien_postulation DATE DEFAULT NULL AFTER reception_inconnu,
  ADD COLUMN date_demande_whatsapp DATE DEFAULT NULL AFTER date_entretien_postulation,
  ADD FOREIGN KEY (invite_par_id) REFERENCES users(id) ON DELETE SET NULL;