Forum: Ruby on Rails MongoDB and Rails 3

Hi!

I am quite new to Ruby on Rails and I am loving it so far. I have to 
work
on a project with MongoDB and I noticed a few tutorials tell us to 
generate
a new app without the ActiveRecord. I wonder if it's the best solution 
Why
isn't a good idea to use ActiveRecord with Mongo? Maybe in the future, 
if
we need to change the database, wouldn't it just the case of changing 
the
database settings if we use ActiveRecord? I think there would be some 
gems
that would make the bridge between ActiveRecord <-> MongoDB transparent 
as
they do with MySQL or Postgres. Innocent me?

Also, because it's schemeless, I am a bit lost when it comes to the
workflow. Migrations are no longer necessary, right? So what would be 
the
best workflow?

We are probably going to use MongoID, but maybe MongoMapper. So, let's 
say
Should I create a model, configure the model accordingly to MongoID and
then controller? Or scaffold / scaffold_controller (never used this 
one)?
(To be honest I never knew what was better if scaffold or model and
controller.)

Hope I am not asking too much!

Thanks.

Thiago.

On Wednesday, October 10, 2012 5:03:25 PM UTC+1, Thiago Rossi wrote:
> they do with MySQL or Postgres. Innocent me?
>
> ActiveRecord is tied to the relational world at a a very deep level - it
just can't talk to mongo and is unlikely ever to. Some other ORMs (such 
as
data mapper) can handle both sql and nosql databases. Even with an ORM 
than
handles both, my personal experience is that you can end up imposing 
your
old relational habits on your non relational database which is non 
optimal.


> Also, because it's schemeless, I am a bit lost when it comes to the
> workflow. Migrations are no longer necessary, right? So what would be the
> best workflow?
>
> You no longer have schema update migrations (eg adding columns). You will
occasionally need to add indexes and you will still need data migrations 
if
you change how store for your data (for example if you switch data from
individual objects to embedded objects)



> We are probably going to use MongoID, but maybe MongoMapper. So, let's
> say Should I create a model, configure the model accordingly to MongoID
> and then controller? Or scaffold / scaffold_controller (never used this
> one)? (To be honest I never knew what was better if scaffold or model and
> controller.)
>
> The controller / forms should be pretty much the same - that's the point
of the ActiveModel interface that Active Record, MongoMapper, Mongoid
conform to.

Fred

I think I didn't realise ActiveRecord and ActiveModel were different
things. Thank you!

Migration was a good way to solve that problem with schemes being 
update,
but when it becomes famous we stop using it. LOL