How can I create database tables from XSD files?

There is a command-line tool called XSD2DB, that generates database from xsd-files, available at sourceforge.

Commercial Product: Altova's XML Spy.

Note that there's no general solution to this. An XSD can easily describe something that does not map to a relational database.

While you can try to "automate" this, your XSD's must be designed with a relational database in mind, or it won't work out well.

If the XSD's have features that don't map well you'll have to (1) design a mapping of some kind and then (2) write your own application to translate the XSD's into DDL.

Been there, done that. Work for hire -- no open source available.