Update action fire an insert query? - ruby-on-rails-3

Question

Hi i know it's silly but true i got this when i edit any entry.
I have an expense model and an expense_line_item and a paid_line_item model, it is created properly when i create a new entry but on editing previous entry it adds a new entry instead of updating, i. e. at update action it fires insert query. here is my code:
My controller:
def new
#menu = 'Expenses'
#page_name = 'Record New Expenses'
#expense = Expense.new
#expense.expense_line_items.build
#expense.paid_line_items.build
#expense.voucher_number = "EXP"+Time.now.to_i.to_s
#from_accounts = TransactionType.fetch_from_accounts(current_company.id, 'payments')
#to_accounts = TransactionType.fetch_to_accounts(current_company.id, 'payments')
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => #expense }
end
end
# GET /expenses/1/edit
def edit
#menu = 'Expenses'
#page_name = 'Edit Expenses Entry'
#expense = Expense.find(params[:id])
#from_accounts = TransactionType.fetch_from_accounts(current_company.id, 'payments')
#to_accounts = TransactionType.fetch_to_accounts(current_company.id, 'payments')
end
# POST /expenses
# POST /expenses.xml
def create
#expense = Expense.new(params[:expense])
#expense.created_by = current_user.id
#expense.company_id = current_company.id
respond_to do |format|
if #expense.save
format.html { redirect_to(#expense, :notice => 'Expense was successfully created.') }
format.xml { render :xml => #expense, :status => :created, :location => #expense }
else
#menu = 'Expenses'
#page_name = 'Record New Expenses'
#from_accounts = TransactionType.fetch_from_accounts(current_company.id, 'payments')
#to_accounts = TransactionType.fetch_to_accounts(current_company.id, 'payments')
format.html { render :action => "new" }
format.xml { render :xml => #expense.errors, :status => :unprocessable_entity }
end
end
end
# PUT /expenses/1
# PUT /expenses/1.xml
def update
#expense = Expense.find(params[:id])
respond_to do |format|
if #expense.update_attributes(params[:expense])
format.html { redirect_to(#expense, :notice => 'Expense was successfully updated.') }
format.xml { head :ok }
else
#menu = 'Expenses'
#page_name = 'Edit Expenses Entry'
format.html { render :action => "edit" }
format.xml { render :xml => #expense.errors, :status => :unprocessable_entity }
end
end
end
My Model:
expense model:
class Expense < ActiveRecord::Base
has_many :expense_line_items
has_many :paid_line_items
accepts_nested_attributes_for :expense_line_items, :reject_if => lambda {|a| a[:account_id].blank? } , :allow_destroy => true
accepts_nested_attributes_for :paid_line_items, :reject_if => lambda {|a| a[:account_id].blank? }, :allow_destroy => true
#validations
validates_presence_of :expense_date, :voucher_number
validates_presence_of :expense_line_items
validates_associated :expense_line_items
validates_presence_of :paid_line_items
validates_associated :paid_line_items
end
expense_line_item:
class ExpenseLineItem < ActiveRecord::Base
belongs_to :expense
end
paid_line_item:
class PaidLineItem < ActiveRecord::Base
belongs_to :expense
end
My form :
<%= form_for(#expense) do |f| %>
<% #expense.expense_line_items.each_with_index do |expense_line_item, index| %>
<%= render "expense_line_items", :expense_line_item => expense_line_item, :index => index %>
<% end %>
<tr id="row_link" valign="top">
<td valign="top" colspan="6">
<%= link_to "Add new row",{:action => :add_row, :index => #expense.expense_line_items.size}, :remote => true %>
</td>
</tr>
<% #expense.paid_line_items.each_with_index do |paid_line_item, index| %>
<%= render "paid_line_items", :paid_line_item => paid_line_item, :index => index %>
<% end %>
<tr id="to_row_link" valign="top">
<td valign="top" colspan="6">
<%= link_to "Add new row",{:action => :add_to_row, :index => #expense.paid_line_items.size}, :remote => true %>
</td>
</tr>
<% end %>
i got frustrated, thanks in advance .

Answer 1

i have found a solution for this problem. When i tried to update a lineitem it take it as a new one hence i have to pass a hidden lineitem_id for update action. i have used
below code :
<%= hidden_field_tag "expense[expense_line_items_attributes][#{index}][id]",expense_line_item.id%>
and it works for me.