如何使用rails将数据库迁移到第一个修订版本，而不首先删除数据库?

I have a database set up for my Rails installation and some migrations set up. I would like to be able to reset my database back down to having no tables/constraints/etc., but can't find a reasonable way to do this without knowing the number of migrations or the timestamp of the first migration. Here are my options as I see them:I have a database set up for my Rails installat