[meowface]

I'm surprised this isn't more of a thing. It seems like the natural evolution of "[X] as code". I've always been a little turned off by migrations (though they were certainly an improvement over the previous situation, which was basically just indeterministic changes on the fly).

[evanelias]

My thoughts exactly. But it's a major paradigm shift for those coming from the world of Rails/Django/etc migrations, and that unfamiliarity understandably leads to some initial resistance and skepticism.

fwiw, other declarative tools are starting to pop up -- besides my tool Skeema, some others I've seen recently are Migra [1] and sqldef [2]. And meanwhile a bunch of enterprise tools for MS SQL Server have operated in the declarative fashion for quite a long time, although usually with GUIs instead of being git / pull-request-driven. So I think/hope it's just a matter of time before this concept becomes more widely known.

[1] https://github.com/djrobstep/migra

[2] https://github.com/k0kubun/sqldef/

[hobs]

It's definitely a thing, eg SQL Server Data Tools has this as a default - Schema Compare and Data Compare, and you can just use declarative approaches to defined your final state and let the tool take care of it.

That being said - if you want to do this the downside is usually that its slow as hell, and the non-migration approaches can cost you downtime.

Generic solutions to specific states often means copying all data somewhere else so you can modify the table and then put it back in a useful fashion - a migration often allows more piecemeal approaches.

Edit: a guy I like wrote a good model/migration set of articles http://dlmconsultants.com/model-vs-mig/