Re: Repairing migrations

Eric Anderson
Thu, 19 Jul 2007 21:09:56 -0000

magic_hat wrote:
> So occassionally my migrations go...uh... off the rails. One of them
> fails, and then I start getting errors about fields already existing,
> etc. Or I make some changes to a database by hand, and then need to
> bring the migration back in synch with the db without nuking the db
> contents.
>
> Sometimes I can turn the schema into a migration to accomplish this.
> But other times the errors continue. Is there a better way to bring a
> migration and existing db into synch?

The biggest thing is to test your migration in the development
environment. That will get rid of many problems. But if for some reason
your migration get''s an error in the production environment you can
just
comment out the part of the migration it has already done (you can tell
by where the error occured) then run again. That migration has not be
checked off yet it will just skip your commented section and pick up
where it left off.

Alternatively you can make the rest of the changes manually and then
just bump the version in the schema table to make rails think you ran it.

Eric