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POHow to get Collection object throug Many to Many relationship in Ruby on Rails
 

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  1. POHow to get Collection object throug Many to Many relationship in Ruby on Rails
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    <p>Friends I've following models</p> <pre><code>class Project &lt; ActiveRecord::Base has_many :milestones_projects has_many :milestones, :through =&gt; :milestones_projects validates :projectname, :presence=&gt;true, :length=&gt; {:maximum=&gt;250}, :uniqueness=&gt;true validates :location,:presence=&gt;true end class Milestone &lt; ActiveRecord::Base has_many :milestones_projects has_many :projects, :through =&gt; :milestones_projects validates :name, :presence =&gt; true, :length =&gt; {:maximum =&gt; 250} validates :days, :presence =&gt; true, :length =&gt; {:maximum =&gt; 3} validates :stage, :presence =&gt; true end class MilestonesProjects &lt; ActiveRecord::Base belongs_to :milestones,:foreign_key =&gt; 'milestone_id' belongs_to :projects,:foreign_key =&gt; 'project_id' end </code></pre> <p>So i have many-to-many relationship between project and milestone.</p> <p>in irb, I want to get collection object, so I'm using as following</p> <pre><code>irb(main):001:0&gt; me=Project.find(1) =&gt; #&lt;Project id: 1, location_id: 1, projectname: "Sample 2", description: "Sample 2", i spublished: true, created_at: "2011-09-02 08:26:41", updated_at: "2011-09-07 10:26:48"&gt; </code></pre> <p>here 'me' is an array contains first project details, and now i"m trying to get milestone details associated with this project. for this I'm trying as follows</p> <pre><code>irb(main):002:0&gt; me.milestones </code></pre> <p>but it's giving me error like</p> <p>NameError: uninitialized constant Project::MilestonesProject from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/base.rb:1205:in <code>compute_type' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:162:in</code>send' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:162:in <code>klass' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:346:in</code>source_reflection' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:346:in <code>collect' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:346:in</code>source_reflection' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/reflection.rb:377:in <code>check_validity!' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/associations/association_proxy.rb:61:in</code>initialize' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/associations/association_collection.rb:23:in <code>initialize' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/associations/has_many_association.rb:11:in</code>initialize' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/associations.rb:1483:in <code>new' from c:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/activerecord-3.0.9/lib/ active_record/associations.rb:1483:in</code>milestones' from (irb):2 from :0</p> <p>so friends please help me..</p> <p>i need to execute some commands like</p> <pre><code>milestone_count=project.milestones.size </code></pre>
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    1. USShreekumar S
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    1. COCould you add the schema of your rails project (the part with milestones, projects, and milestone_projects). And could you edit your post so that the stack trace is indented 4 spaces?
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