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PORails nested form on HABTM: how to prevent duplicate entry?
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  1. PORails nested form on HABTM: how to prevent duplicate entry?
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    copied!<p>I have simple app with 3 tables in DB and 'many-to-many' relationships.</p> <pre><code># Model Employee class Employee &lt; ActiveRecord::Base has_and_belongs_to_many :phonenumbers accepts_nested_attributes_for :phonenumbers, :allow_destroy =&gt; true attr_accessible :last_name, :first_name, :middle_name, :phonenumbers_attributes end # Model Phonenumber class Phonenumber &lt; ActiveRecord::Base has_and_belongs_to_many :employees attr_accessible :number accepts_nested_attributes_for :employees end </code></pre> <p>I have 'employees_phonenumbers' join-table with 'employee_id' and 'phonenumber_id' columns.</p> <pre><code># View &lt;%= form_for @employee, :url =&gt; { :action =&gt; :create } do |f| %&gt; &lt;%= f.label "Last name" %&gt; &lt;%= f.text_field :last_name %&gt; &lt;%= f.label "First name" %&gt; &lt;%= f.text_field :first_name %&gt; &lt;%= f.label "Middle name" %&gt; &lt;%= f.text_field :middle_name %&gt; &lt;%= f.fields_for :phonenumbers do |phonenumber| %&gt; &lt;%= phonenumber.label "Phone number" %&gt; &lt;%= phonenumber.telephone_field :number %&gt; &lt;% end %&gt; &lt;%= f.submit "Create" %&gt; &lt;% end %&gt; # Controller def create @employee = Employee.new(params[:employee]) @employee.save ? (redirect_to :action =&gt; :index) : (render "new") end </code></pre> <p>Now if I create a user: 'John' with phone number '555', it's OK.</p> <p>But if I want to create a user 'Larry' with the same phone number '555', there's a dublicate of '555' entry in the DB.</p> <p>How do I prevent this?</p> <p><strong>UPDATE:</strong> My logic is: If there is number '555', then do not create a new one, use existing. If there is no such a number, then create a new one and use it.</p>
 

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