dbdsgnris a brilliant application all you need to use it is a Google account. dbdsgnrlets you create your database tables and set all your data types that you would like and then set relationships between tables with a foreign key.
Once you're done setting up your tables you can save your scheme for later use or generate the sql ready to copy and paste into your favourite database management tool without you having to write a single line of code.
Check it out for yourself: http://dbdsgnr.appspot.com/