Nate, > I've been experimenting with DM 1.0.0.rc3 and auto-migrations don't > appear to be working as expected. Specifically, it appears that > modifications to columns are not reflected in the DB if the columns > already exist.
This is actually by design. The auto-upgrade feature is only *additive*, in that it will add things that don't exist, but it will not change anything that is present. So it adds new tables and columns, but does not change any columns that are present. There will be some work after 1.0 to make auto-upgrading a bit smarter, but up until now we've been conservative in what it does. Anytime to loosen a constraint it should be fairly easy to make the change. In some cases it might even be possible to tighten constraints if we inspect the data beforehand. (for example, changing CHAR(20) to CHAR(10) might be possible as long as SELECT MAX(LENGTH(col)) is <= 10) The reason we've avoided this up until now is that it can get complex quickly, and even a tiny mistake on our end may cause a data loss. If we do approach this in the future it will have to be extremely well specced and tested before we'll release it to the public. At the moment though I personally don't see auto-upgrading as being very useful, since there will always be things it can't handle automatically like renames and deletions. For me it's more a question between auto-migrating (which is destructive) and classic migrations. -- Dan -- You received this message because you are subscribed to the Google Groups "DataMapper" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/datamapper?hl=en.
