ruby-on-rails – NameError：uninitialized constant User

rails console
User.all

我从控制台收到以下错误：

NameError: uninitialized constant User
from (irb):2
from /Users/msarr/.rvm/gems/ruby-2.2.1/gems/railties-4.2.5.1/lib/rails/commands/console.rb:110:in `start'
from /Users/msarr/.rvm/gems/ruby-2.2.1/gems/railties-4.2.5.1/lib/rails/commands/console.rb:9:in `start'
from /Users/msarr/.rvm/gems/ruby-2.2.1/gems/railties-4.2.5.1/lib/rails/commands/commands_tasks.rb:68:in `console'
from /Users/msarr/.rvm/gems/ruby-2.2.1/gems/railties-4.2.5.1/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /Users/msarr/.rvm/gems/ruby-2.2.1/gems/railties-4.2.5.1/lib/rails/commands.rb:17:in `<top (required)>'
from /Users/msarr/Desktop/deployment/YouServe/bin/rails:9:in `<top (required)>'
from /Users/msarr/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Users/msarr/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from -e:1:in `<main>'

这是我的Gemfile：

source 'https://rubygems.org'
  ruby '2.2.1'
  gem 'rails','4.2.5.1'
  gem 'sass-rails','~> 5.0'
  gem 'uglifier','>= 1.3.0'
  gem 'coffee-rails','~> 4.1.0'
  gem 'jquery-rails'
  gem 'turbolinks'
  gem 'jbuilder','~> 2.0'
  gem 'carrierwave'
  gem 'mini_magick'
  gem 'fog'                  
  gem 'administrate'
  gem 'devise'
  gem 'devise_invitable'
  gem 'foundation-rails','~> 5.5'
  gem 'high_voltage'
  gem 'simple_form'

 group :development,:test do
  gem 'byebug'
  gem 'sqlite3'
end
group :development do
  gem 'web-console','~> 2.0'
  gem 'spring'
  gem 'better_errors'
  gem 'hub',:require=>nil
  gem 'quiet_assets'
  gem 'rails_layout'
end

group :production do
 gem 'pg'
 gem 'rails_12factor'
 gem 'unicorn'
end