I've been playing lucidchart for a while. I mainly use it to draft out my ERD but it can actually export to code for your selected DBMS. It's free for your 1st three projects:
https://www.lucidchart.com/pages/

I usually use PostgreSQL and often use pgAdmin for a more visual representation of my database. It's open source and free:
https://www.pgadmin.org/

Not certain of tools for other management systems outside of PostgreSQL. I'm sure there are many but I don't know them off the top of my head.

Hope this was helpful