Exploring Active Record

An anonymous reader writes "Everyone knows that no programming language is a perfect fit for every job. This article launches a 'new series by Bruce Tate that looks at ways other languages solve major problems and what those solutions mean to Java developers. He first explores Active Record, the persistence engine behind Ruby on Rails.'"

Comments

Re:Still looking for an IDE

[lifeisgreat]

Try RadRails - it's the best Rails-specific IDE I found during my brief searching. I noticed a few bugs, but at least it's still being developed.

Rails rocks (but isn't a silver bullet)

[PetriWessman]

I've been playing around with Rails and AR quite a bit lately, and it has changed the way I think about programming in many (positive) ways. I come from a heavy Java / J2EE background (do that for a living, serverside systems), and Ruby + Rails is a breath of fresh air. Ruby is simply a wonderful language, there is something very "zen" about it, and Rails is inspired. Sure, it builds on a lot of old concepts, but the brilliance is where it leverages the power of the Ruby language to do things in very efficient and nice ways.

Yes, there is a lot of "black automagic" involved in Rails. It's where the power is, and you can override pretty much everything is you want to. If you're uncomfortable with magic stuff happening behind the scenes and don't want to learn Ruby so you really understand that magic, Rails might not be for you.

I'd claim that pretty much every serious programmer (VB scripters don't count :) should learn Ruby, at least the basics. It might not become your new favorite language (like it has for me), but it will give you a fresh new perspective on how to code stuff.

Ruby does have a few downsides:

• There is no Unicode support. For a language coming from Japan that's surprising (and sucks). I'm given to understand that fixing this is in the roadmap for Ruby(?).
• It's an interpreted language (like Perl, Python etc), so if speed really is an issue for you then it's not a good choice (for most things nowadays, Ruby is more than fast enough)
• The scoping of variables in blocks is a bit funky.
• Some of the organization in the standard libraries is a bit weird, and there is some repetition of functionality. I think this is due to historical reasons (std lib code has evolved over the years)

(there are probably more, but I'm still only learning the language)

As for Rails, well, again there are downsides. Nothing is perfect.

• No Unicode support (inherits Ruby weakness). For web apps, this really sucks.
• Poor localization support in general (again, sucks).
• ActiveRecord is nice, but works best for from-the-ground-up projects. Integrating with a legacy schema might get ugly, a mapping layer (like Java's Hibernate) would work better there.
• No support for clustering and other heavy-lifting technologies. If you're building a seriously big app, Rails might not be the optimal choice. But face it, 99% of web apps don't need stuff like that. Right tool for the job, and all that
• Still a young framework, and evolving. This is both good and bad. Bad, since the framework is changing while you code. Good, since it means that bugs (and maybe the above weaknesses, too) are getting fixed.

So: it's not a silver bullet. Nothing is. But for a large majority of the modern-day web app use cases, it's very nice, productive and, well, elegant. It lets you to do quick prototypes and keep your code clean, you don't end up with the insecure and ugly mess most PHP apps end up being.

Re:Rails rocks (but isn't a silver bullet)

[consumer]

I don't know about Python, but Perl and more recent versions of PHP are not interpreted. They are compiled to opcodes and then the opcodes are executed. With a persistent environment like mod_perl, you are always running the compiled code after the inital load. Both of them have much better base language performance than Ruby does at this point. I expect that Ruby will eventually work this way too.

Re:Rails rocks (but isn't a silver bullet)

[revscat]

Well rails is a very good framework + toolset, but like every other enforcing toolset which tries to cover a lot of ground by automating stuff it has a huge problem, follow the road and you are set, if you cannot follow the road you are screwed.

I have seen this complaint lodged many times, and at first I was concerned about it because of this, but I have yet to actually run into it. Rails is flexible enough that all the conventions it uses are overridable, and if you know of any exceptions to this please let me know, because I am still evaluating it. For example: by default AR assumes your primary key column is named id, but you can override that per-table if you like, or globally via environment.rb:

ActiveRecord::Base.primary_key_prefix_type = :table_name_with_underscore

Similarly, while AR expects plural table names, you can override that with the following:

ActiveRecord::Base.pluralize_table_names = false

So I don't agree with the (overly stated, IMHO) belief that Rails falls on its face when you move outside its conventions. My experience does not match this.

Re:language matters a great deal

[aricusmaximus]

Most studies show that this is blatantly untrue -- programmer productivity is generally independent of language chosen.

Excuse me? Which studies?

Certainly not this one:

http://page.mi.fu-berlin.de/~prechelt/Biblio/jccpp rt_computer2000.pdf

Nor this one:

http://www.erlang.se/publications/Ulf_Wiger.pdf

Nor even this one:

http://www.theadvisors.com/langcomparison.htm

And this well-regarded programmer certainly doesn't agree that the choice of language doesn't matter:

http://www.mindview.net/WebLog/log-0025

I tell you what -- interview a group of experienced programmers for a prospective project to write a database-backed web application with complex requirements. Tell them that they will be required to program in assembly language because "most studies show that... programmer productivity is generally independent of language chosen." Record their responses and post them to Slashdot.

Re:Hmm...

[Decaff]

That stuff sounds really interesting. Do you have links for some of the research?

Yes. The best place to look is the specifications at the JCP.

JDO 2.0 is

http://www.jcp.org/en/jsr/detail?id=243

EJB 3.0 (including JPA) is

http://www.jcp.org/en/jsr/detail?id=220

I've heard of hibernate, but not the JPA. Is that going to be part of the standard JRE? I hate having my code rely on goofy 3rd party add-ons.

JPA is going to be a standard part of J2EE, but can be used stand-alone with JRE. There are many vendors providing implementations - Sun, Oracle, JBoss, BEA, JPOX, Versant. A significant number of these are going to be open source (JBoss, Oracle, BEA). Hibernate is also going to provide an implementation of JPA.