Is their any Database ERD for magento 2?
You can build it by yourself by using tool, it's not that hard.
I remember once I used DbSchema tool to generate ERD for Magento1:
Well you have to import a er diagram drawn from a 3rd party software for this purpose. In this case I suggest looking in Creately entity relationship diagram tool community
You can use a diagram tool like Creately to draw entity relationship diagrams. There are many templates and examples to get started.