I'm writing a simple app that takes standard input from the user. As for the email entry, I have it verify if it is in a standard email format and then have it list the problems like this when a ne...

We just upgraded our virtual machines to what I thought was an identical ruby configuration (via RVM... Ruby 1.9.2, Rails 3.0.7, DataMapper 1.1.0). The biggest difference was that we went from MySQ...

I'm reading the architectural patterns chapter of POEAA, and Fowler says that "As the domain logic gets more complicated and you begin moving toward a rich Domain Model (116), the simple approach o...

So I'm just curious about this: DataMapper uses a mixin for its Models class Post include DataMapper::Resource While active-record uses inheritance class Post < ActiveRecord::Base Does a...

I am curious on what you guys think about DataMapper and what benefits does it bring over the new and improved ActiveRecord in Rails 3. I appreciate your opinions.

I am very new to Ruby . I installed DataMapper and I am trying to install dm-mysql-adapter-1.0.2 gem . But when I try to install , I get the below error . I am using ubuntu OS . vinoth@vinoth-lapt...

im a beginner with DataMapper ORM, so i have question about complex querying. First, here is simplified data objects: class User property :id, Serial property :login, String has n, :actions...

Which ORM is best to use with a new Rails 3 app against a legacy MySQL 5.1 database? I do not expect to ever run a migration against this database (though the schema may change from time to time), ...

I'm working with Doctrine2 for the first time, but I think this question is generic enough to not be dependent on a specific ORM. Should the entities in a Data Mapper pattern be aware - and use -...

Does anybody know the magic incantation required to get a Sinatra application that uses DataMapper up and running on Heroku's Bamboo stack? The Bamboo stack doesn't include any pre-installed system...

I have managed to run a basic rails app1 on App Engine using: http://gist.github.com/268192 So, on my basic app2, I install CE, which works fine on local machine. (communityengine.org) But, when ...

A colleague of mine is currently designing SQL queries like the one below to produce reports, which are displayed in excel files through an external data query. At present, only reporting processes...

I have a table called Cat, and an PHP class called Cat. Now I want to make a CatDataMapper class, so that Cat extends CatDataMapper. I want that Data Mapper class to provide basic functionality fo...

I started learning Datamapper and what I liked about it was that I can write my models with real inheritance. Now I wonder, if it is possible to be more advanced about this: class Event include ...

I am working on a simple app in Sinatra with DataMapper. I want to see the queries that DM is created for my various chained finders, etc. I have tried: DataMapper::Logger.new(STDOUT, :debug) i...

When I try to do this in Sinatra, class Comment include DataMapper::Resource property :id, Serial property :body, Text property :created_at, DateTime end get '/show' do comment = Comment.a...

Up until now I've been using Active records in all my c# database driven applications. But now my application requires my persistence code being split from my business objects. I have read a lot of...

I'm building an app in PHP and I'm using the data mapper pattern for my DB access. I was considering using the Observer pattern to have all my mappers observe the entities they create, so that they...

I was looking at DataMapper, which appeared at first glance to use the ActiveRecord ORM pattern. Other people said that it uses the DataMapper and/or the Domain Object pattern. What is the differ...