Can update the order of a page and all pages in between old and new order indices safely

pageorder-atomically-update.sql

UPDATE page, (SELECT pageorder as oldorder FROM page WHERE id = :pgid) as t2 SET page.pageorder = CASE
  WHEN id = :pgid THEN :neworder
  WHEN page.pageorder <= :neworder AND page.pageorder > t2.oldorder THEN page.pageorder-1
  WHEN page.pageorder >= :neworder AND page.pageorder < t2.oldorder THEN page.pageorder+1
  ELSE page.pageorder
END
WHERE page.pageorder >= LEAST(:neworder, t2.oldorder) AND page.pageorder <= GREATEST(:neworder, t2.oldorder);