小编dem*_*and的帖子

我正在使用Ruby on Rails 3.1预发行版.我喜欢使用PostgreSQL,但问题是安装pggem.它给了我以下错误:

$ gem install pg
Building native extensions.  This could take a while...
ERROR:  Error installing pg:
    ERROR: Failed to build gem native extension.

        /home/u/.rvm/rubies/ruby-1.9.2-p0/bin/ruby extconf.rb
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
 --with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for …

我正在使用emacs 23.3.我需要更改字体大小和字体类型,任何人都可以帮助我吗？

有人知道任何好的HTML5和CSS3教程吗？

我正在创建一些自定义异常,如下所示

LIB/exceptions.rb

module Exceptions
  class MemberOverFlow < StandardError
  end
  rescue_from MemberOverFlow do |exception|
    redirect_to root_url, :alert => exception.message
  end
end

我用来像这样引发异常.

raise Exception::MemberOverFlow"member count overflow"

它给出了以下错误

NoMethodError in MembersController#create

undefined method `MemberOverFlow' for Exception:Class

任何人都可以告诉我什么是问题

谢谢

如何使用mysql创建rails 3.1应用程序.以下命令用于使用sqlite数据库创建项目.

rails new depot

我想使用mysql然后sqlite.所以任何人都可以告诉我如何用mysql创建一个项目.

谢谢

现在我将rails 3.0.7升级到rails 3.1 pre版本.当我创建一个示例项目时,它工作正常.创建一个脚手架后,我尝试迁移,但它让我的耙子中止了!信息.

在这里我的代码

rails g scaffold product name:string price:decimal category:string
      invoke  active_record
      create    db/migrate/20110517090853_create_products.rb
      create    app/models/product.rb
      invoke    test_unit
      create      test/unit/product_test.rb
      create      test/fixtures/products.yml
       route  resources :products
      invoke  scaffold_controller
      create    app/controllers/products_controller.rb
      invoke    erb
      create      app/views/products
      create      app/views/products/index.html.erb
      create      app/views/products/edit.html.erb
      create      app/views/products/show.html.erb
      create      app/views/products/new.html.erb
      create      app/views/products/_form.html.erb
      invoke    test_unit
      create      test/functional/products_controller_test.rb
      invoke    helper
      create      app/helpers/products_helper.rb
      invoke      test_unit
      create        test/unit/helpers/products_helper_test.rb
      create  app/assets/stylesheets/scaffold.css.scss
      invoke  assets
      create    app/assets/javascripts/products.js.coffee
      create    app/assets/stylesheets/products.css.scss
rake db:migrate
==  CreateProducts: migrating =================================================
-- create_table(:products)
   -> 0.0053s
==  CreateProducts: migrated (0.0054s) ======================================== …

如何使用savon gem 访问Magento SOAP API.有什么例子我可以用来快速前进吗？

谢谢