updateArticleCover artId Nothing prefix conn =
  execute conn sql (Only artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = NULL WHERE `id` = ?" ]
updateArticleCover artId Nothing prefix conn =
  execute conn sql (Only artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = NULL WHERE `id` = ?" ]
updateArticleCover artId Nothing prefix conn =
  execute conn sql (Only artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = NULL WHERE `id` = ?" ]