Well, I think Chinese food is far different from Thai food. Shanghai food just play a part role of Chinese food. Well, you could try the food from all of China in Shanghai. Or, please go to Suzhou for more delicious dishes and snacks. There are many time-honored restaurants there. My suggestion is that you read about this website's introduction on Chinese food in advance: https://www.travelchinaguide.com/intro/cuisine_drink/

Hi there,
Please don't mix up Shanghai food with Cantonese food. There's many differences that's too much to explain here. If you are looking for the most authentic roast Peking duck place, go to below:

Quan Ju De 全聚德 pronounced (Chuan Joo Der for westerners.. )
Address: 786 Huai Hai Zhong Road, 4th Floor
5404-5799 to reserve a table if you've got a large group.
I usually go here for group dinners when I hang w/ my Shanghai friends.. the place originated in Beijing where the roast duck is the best.

There's so much more to Shanghai food.. you don't even know.. *sigh