Hibernate on Ruby


#1

Any ideas on using Hibernate OR/M from within Ruby?


#2

Why, when you have Og, ActiveRecord and a few other interesting
choices?

T.


#3

ActiveRecord is great for small-to-medium things, but does quickly show
it’s limits on large things. NOTE: Please, do not turn this thread
into a flame war. See Martin F.'s discussion of ActiveRecord
versus DataMapper. Rails’s ActiveRecord is based on Fowler’s
ActiveRecord pattern, wheras Hibernate is a DataMapper, which Fowler
himself favors for complicated mappings.

See DHH’s post:
“No, you don’t get the full offer of opportunities that straight OO
with a data mapper holds. I’d like to think, though, that Active Record
gives you 80% of the features for 20% of the effort.”
http://www.loudthinking.com/arc/000209.html

Example for me:
Let’s say I have a class hierarchy, in which a particular field is
stored direclty in the db for one class, and calculated using a simple
SQL formula for other other classes. How can I use the DB to query the
tree for all objects where field == aVal.

Answer: In ActiveRecord - you can’t (w/o major hacking). You need to
instantiate each one from the db, and then use Ruby to check each one.


#4

List R. wrote:

ActiveRecord is great for small-to-medium things, but does quickly show
it’s limits on large things. NOTE: Please, do not turn this thread
into a flame war. See Martin F.'s discussion of ActiveRecord
versus DataMapper. Rails’s ActiveRecord is based on Fowler’s
ActiveRecord pattern, wheras Hibernate is a DataMapper, which Fowler
himself favors for complicated mappings.

See DHH’s post:
“No, you don’t get the full offer of opportunities that straight OO
with a data mapper holds. I’d like to think, though, that Active Record
gives you 80% of the features for 20% of the effort.”
http://www.loudthinking.com/arc/000209.html

Example for me:
Let’s say I have a class hierarchy, in which a particular field is
stored direclty in the db for one class, and calculated using a simple
SQL formula for other other classes. How can I use the DB to query the
tree for all objects where field == aVal.

Answer: In ActiveRecord - you can’t (w/o major hacking). You need to
instantiate each one from the db, and then use Ruby to check each one.

Google up Og and Kansas and see if either suits you better.
Both take a modeling approach perpendicular to AR. There
are others also, I am sure.

Or, of course, you could restructure your data :slight_smile:

E


#5

Zed A. Shaw wrote:

No, that’d actually involve admitting he is wrong. The day a
programmer actually admits he’s wrong is the day Satan ice skates
around Times Square in July eating Tasti-Delight while wearing long
underwear.

Yeah, that’s the way, go off on a tangent and berate someone for asking
a simple question, without actually giving him a straight answer.

Now I remember why I unsubscribed from this group before…


Neil S. - removed_email_address@domain.invalid

‘A republic, if you can keep it.’ – Benjamin Franklin


#6

On Tue, 13 Dec 2005 07:55:02 +0900
Eero S. removed_email_address@domain.invalid wrote:

Google up Og and Kansas and see if either suits you better.
Both take a modeling approach perpendicular to AR. There
are others also, I am sure.

Or, of course, you could restructure your data :slight_smile:

No, that’d actually involve admitting he is wrong. The day a
programmer actually admits he’s wrong is the day Satan ice skates
around Times Square in July eating Tasti-Delight while wearing long
underwear.

For another great example of “fighting to always be right” refer to any
thread about plural table names (either side).

Zed A. Shaw


#7

Thanks for the support Neil.


#8

On 12/12/05, removed_email_address@domain.invalid removed_email_address@domain.invalid wrote:

Thanks for the support Neil.

I won’t claim to support this idea. Personally, I think it’s like
having your whole BMW chromed. Heh.

However, you should be able to actually do it with something like:
http://rjni.rubyforge.org/
…or:
http://raa.ruby-lang.org/project/rjb/

I’m not sure if there’s a good way to gen the XDoclet tags in Ruby.
Presumably there’s a fancy ERb trick you can use.


#9

removed_email_address@domain.invalid ha scritto:

Any ideas on using Hibernate OR/M from within Ruby?

probably the only chance is using jruby, but are you sure you can’t do
what you want with Og ?