updateArticleCover :: ID -> Maybe File -> MySQL Int64
updateArticleCover artId (Just cover) prefix conn =
  execute conn sql (encode cover, artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = ? WHERE `id` = ?" ]
updateArticleCover :: ID -> Maybe File -> MySQL Int64
updateArticleCover artId (Just cover) prefix conn =
  execute conn sql (encode cover, artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = ? WHERE `id` = ?" ]
updateArticleCover artId (Just cover) prefix conn =
  execute conn sql (encode cover, artId)
  where sql = fromString $ concat [ "UPDATE `", prefix, "_articles` SET `cover` = ? WHERE `id` = ?" ]