xdb

This tool is kind of a clone of rails database migrations. It can be used to generate an SQL script to migrate a database up or down from one version to another. For that it needs no database access. So it is database independent but you have to say what the current and what the target version is.

To prevent mistakes there is by default a transaction around. Which is currently not database independent. I try to find a simple solution for this issue, but for now it should work for Postgres and MySql.