def _fetch_info(self, room, jid, nick, d):
  if jid:
   if nick: c = self.db.query('select * from users where room=? and (jid=? or nick=?)',\
   (room, jid, nick))
   else: c = self.db.query('select * from users where room=? and jid=?', (room, jid))
  else: c = self.db.query('select * from users where room=? and nick=?', (room, nick))
  r = c.fetchall()
  if len(r) == 0: d.errback(nickstorage_not_found(''))
  elif len(r) == 1: d.callback(r)
  else:
   if jid and nick: d.callback(r)
   else:
    self.bot.log.err_e('Problems with database: jid %s or nick %s is not unique in room %s' % (jid, nick, room))
    d.errback(nickstorage_error('db'))