On 9 March 2010 18:59, Sumeet Panchal <[email protected]> wrote: > So problem is I have to convert, the 200 table database to EAV. Has > anybody worked with > EAV model, know its pros cons, and how to do this in rails.
The only EAV data model I've used in anger is the back-end of the PHP ecommerce system Magento. It's a very powerful pattern, but has its own limitations (not least that it's a total nightmare to query manually, and tends to be a little slower than row modelling patterns. But, and I'm happy for the more computer science-y bods to correct me, Rails with ActiveRecord is very tightly bound to the row model of data - in your change, all the magic of associations and relationships won't work. It seems the task that faces you to implement EAV is a massive one... you're pretty much saying "I'm going to write a new Ruby-based web application framework, and use EAV". Of course, you might be able to make a "acts_as_eav" plugin, which could use AR associations of Attributes and Values with (as Andy says) method_missing? calls to act *like* an EAV model - so you can keep the core of AR, but include the flexibility of EAV at will. Maybe this "plugin" approach is likely to be easier with Rails 3 - which isn't necessarily so locked to AR... Let's go back to the problem (as we are, at heart, looking for ways to implement the solution you've decided on, rather than figuring which solution to use to address a problem) - you have 200 tables (that's a lot!). Do they all map to AR associations? What do they all do? Is there not a easy ORM approach that will suffice rather than EAV? I'd *love* to see an easy to use EAV option for Rails - but I'd imagine you need to be a "Zed Shaw"/"Hiro Protagonist" to write it... -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" 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/rubyonrails-talk?hl=en.
