Are there any tools to go from ERD to DB design and vice versa? I'm learning DB design and looking for some tools, preferably open source software, that could help go from an ERD to a DATABASE and vice versa.

For the record, the database i'm using is MySQL.
Since you're using MySQL, you might want to take a look at MySQL Workbench.

It might not quite display the ERDs you're expecting but it gets the job done.

And it does have an import feature. I have only used it to import SQL files but apparently you can import from existing MySQL databases.



Also, a long time ago I found the following tools; but were not quite useful to me back then (perhaps they've matured by now):


Database Design Tool - DDT
Mogwai ERDesigner