param is missing or the value is empty: item <p><strong>items_controller.rb</strong></p> <pre><code>class ItemsController &lt; ApplicationController def index @items = Item.all render text: @items.map{ |i| "#{i.name}: #{i.price}" }.join('&lt;br/&gt;') end def create item_params = params.require(:item).permit(:name, :description, :price, :real, :weight) @item = Item.create(item_params) render text: "#{@item.id}: #{@item.name}(#{!@item.new_record?})" end end </code></pre> <blockquote> <p>error : param is missing or the value is empty: item</p> <p>Rails.root: E:/work/my_store_2</p> <p>Application Trace | Framework Trace | Full Trace app/controllers/items_controller.rb:9:in `create' Request</p> <p>Parameters:</p> <p>{"name"=>"car1", "description"=>"good car", "price"=>"500000", "weight"=>"0", "real"=>"1"}</p> </blockquote> <p><strong>console</strong></p> <pre><code>Started GET "/items/create?name=car1&amp;description=good+car&amp;price=500000&amp;weight=0&amp;real=1" for 127.0.0.1 at 2015-06-18 21:25:39 +0300 Processing by ItemsController#create as HTML Parameters: {"name"=&gt;"car1", "description"=&gt;"good car", "price"=&gt;"500000", "weight"=&gt;"0", "real"=&gt;"1"} Completed 400 Bad Request in 2ms ActionController::ParameterMissing (param is missing or the value is empty: item): app/controllers/items_controller.rb:9:in `create' </code></pre> <p><strong>where is my mistake?</strong></p>