Question

Invoice item is a model in our rails 3.2.8 app. Its definition is:

class InvoiceItem < ActiveRecord::Base 

  belongs_to :invoice
  belongs_to :quote_test_item, :class_name => 'QuoteTestItem'
  belongs_to :lease_usage_record, :class_name => 'LeaseUsageRecord'

  validates :lease_usage_record_id, :uniqueness => { :scope => :invoice_id }, :unless => "lease_usage_record_id.nil?"

end

There are 3 associations. If i is an invoice item object. i.quote_test_item will create error (in rails console):

irb(main):037:0> i.quote_test_item
NameError: uninitialized constant InvoiceItem::quote_test_item

i is:

irb(main):038:0> i
=> #<InvoiceItem id: 6, invoice_id: 6, lease_usage_record_id: nil, created_at: "2012-07-25 19:28:37", updated_at: "2012-07-25 19:28:37", quote_test_item_id: 1>

But both i.invoice and i.lease_usage_record went through and did not create any error. For example:

irb(main):036:0> i.lease_usage_record
=> nil

Why only i.quote_test_item created error? Thanks so much.

Answer 1

Make sure you have performed all migrations. You might also want to check whether your QuoteTestItem (which by the way, you don’t have to specify the :classname since its inferred) to check whether you have a corresponding has_one :invoice_item or has_many :invoice_items, depending on how your modelling it.