Someone here likes to spit shit from his mouth. If you hate shanghainese, hate them. You have mental freedome to hate anybody, but verbal attack is a crime. When shanghai contributed its money to many provinces of the country, she is still attacked by many Countryside Men, you. Those people shut you asshole up.
PUn: if you know manderin, you can use manderin or at least with Chinese translation, otherwise you waste many people's time here. I guess many shanghai people know manderin too.