Question

Rails 3.1, Ruby 1.87 (don’t hate me). I watched the Railscasts on Nested Forms; I only put that in so you can point out where I might have missed something in the Railscasts if you know them.

Note: I added @sample_data_set.build_sample_data_template but got “unknown attribute: sample_data_set_id” on the post instead [the code is also posted with the new below).

Using a Nested form on Create/New; hit Submit and get:

ActiveRecord::UnknownAttributeError (unknown attribute:
sample_data_templates):
app/controllers/sample_data_sets_controller.rb:50:in new'
app/controllers/sample_data_sets_controller.rb:50:increate’

Sample Data Set Model:

class SampleDataSet < ActiveRecord::Base
  has_one :sample_data_template, :dependent => :destroy
  accepts_nested_attributes_for :sample_data_template
end

Sample Data Template Model:

class SampleDataTemplate < ActiveRecord::Base
  belongs_to :sample_data_set
   #Random info generation
  def self.name_gen(*prepend)
    character_map =  [('a'..'z'),('A'..'Z')].map{|i| i.to_a}.flatten
    name  =  (0..8).map{ character_map[rand(character_map.length)]  }.join

    if prepend[0].nil? || prepend[0] == ""
      return name
    else
      return prepend[0].to_s + "_" + name
    end
  end

  def self.ssn_gen
    #broke this out as its own method in case someone wants some logic later one
    ssn = ""
    3.times do
      ssn = ssn + (100..999).to_a.choice.to_s
    end
    return ssn
  end

  def self.row_gen(row_count)
    @data_rows = Array.new
    i = 0
    until i > row_count do
      @row = SampleDataSet.first
      @row.officialFirstName  = SampleDataTemplate.name_gen
      @row.officialLastName   = SampleDataTemplate.name_gen
      @row.emailAddresses     = @row.officialFirstName + @row.officialLastName + "@aaa.aaa.edu"
      @row.ssn                = SampleDataTemplate.ssn_gen
      @data_rows << @row
      i += 1
    end

    return @data_rows
  end
end

Sample Data Controller#New

  def new
    @sample_data_set = SampleDataSet.new
    @sample_data_set.build_sample_data_template #after adding this I get error:unknown attribute: sample_data_set_id     
    respond_to do |format|
      format.html # new.html.erb
      format.json { render :json => @sample_data_set }
    end

Sample Data Controller#Create

  def create
    @sample_data_set = SampleDataSet.new(params[:sample_data_set])

    respond_to do |format|
      if @sample_data_set.save
        format.html { redirect_to @sample_data_set, :notice => 'Sample data set was successfully created.' }
        format.json { render :json => @sample_data_set, :status => :created, :location => @sample_data_set }
      else
        format.html { render :action => "new" }
        format.json { render :json => @sample_data_set.errors, :status => :unprocessable_entity }
      end
    end
  end
  end

Update, added form piece

  <div class="sample_fields">
    <%= f.fields_for :sample_data_templates do |builder| %>
      <%= render "sample_data", :f => builder%>
    <% end %>
  </div>

Update, Schema:

ActiveRecord::Schema.define(:version => 20120103172936) do

  create_table "sample_data_sets", :force => true do |t|
    t.string   "title"
    t.text     "description"
    t.string   "created_for"
    t.string   "created_by"
    t.integer  "number_of_records"
    t.integer  "sample_data_template_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "sample_data_templates", :force => true do |t|
    t.integer  "sample_data_set_id"
    t.string   "irn"
    t.string   "ssn"
    t.string   "officialLastName"
    t.string   "officialFirstName"
    t.string   "emailAddresses"
    t.string   "campusNum"
    t.string   "internationalId"
    t.string   "internationalIdCountry"
    t.string   "gender"
    t.string   "officialMiddleInitial"
    t.string   "previousLastName"
    t.string   "previousFirstName"
    t.string   "previousMiddleInitial"
    t.string   "addressLine1"
    t.string   "addressLine2"
    t.string   "addressLine3"
    t.string   "city"
    t.string   "state"
    t.string   "zipCode"
    t.string   "province"
    t.string   "homeAreaCode"
    t.string   "homePhoneNumber"
    t.string   "homePhoneExtenstion"
    t.string   "homePhoneCountryCode"
    t.string   "workAreaCode"
    t.string   "workPhoneNumber"
    t.string   "workExtenstion"
    t.string   "workPhoneCountryCode"
    t.string   "faxAreaCode"
    t.string   "faxPhoneNumber"
    t.string   "faxExtension"
    t.string   "faxCountryCode"
    t.string   "race"
    t.string   "previousDegree"
    t.string   "region"
    t.string   "foreignTranscript"
    t.string   "apolloEmployee"
    t.string   "nursingLicenseExpiration"
    t.string   "nursingInsuranceExpiration"
    t.string   "otherInsuranceExpiration"
    t.string   "program"
    t.string   "version"
    t.string   "groupId"
    t.string   "team"
    t.string   "enrollmentUserId"
    t.string   "admissionsUserId"
    t.string   "oldProgram"
    t.string   "oldVersion"
    t.string   "galaxyStudentOid"
    t.string   "suffixOne"
    t.string   "suffixTwo"
    t.string   "employeId"
    t.string   "promoCode"
    t.string   "revCampusOid"
    t.string   "FerpaNotes"
    t.string   "isWavierHigh"
    t.string   "executingUserId"
    t.string   "totalDeclaredExtCredits"
    t.datetime "insuranceExpireDate"
    t.datetime "acknowledgementDate"
    t.datetime "scheduledReentryDate"
    t.datetime "scheduledStartDate"
    t.datetime "dateOfBirth"
    t.datetime "enrollAgreeSignDate"
    t.boolean  "usCitizen"
    t.boolean  "financialAid"
    t.boolean  "overrideFlag"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

Answer 1

Does sample_data_templates table have a sample_data_set_id column? Perhaps you didn’t add it to the migration or did not run the migration?