诗歌rails之 Rails 2.3 Extras

 1 # find in batches
 2 Product.count
 3 Product.find_in_batches(:batch_size => 10) do |batch|
 4   puts "Products in batch: #{batch.size}"
 5 end
 6 Product.each(:batch_size => 10) do |product|
 7   puts product.name
 8 end
 9 
10 # scoped_by
11 Product.scoped_by_price(4.99).size
12 Product.scoped_by_price(4.99).first
13 Product.scoped_by_price(4.99).scoped_by_category_id(3).first
14 
15 # try method
16 Product.find_by_price(4.99).name
17 Product.find_by_price(4.95).name
18 Product.find_by_price(4.95).try(:name)
19 Product.find_by_price(4.99).try(:name)
20 
21 # product.rb
22 default_scope :order => "name"
23 
24 # categories_controller.rb
25 render 'new'
26 render 'products/edit'
27 
28 <!-- products/index.html.erb -->
29 <%= render @products %>
30 
31 <!-- products/show.html.erb -->
32 <%= render @product %>
33 
34