在 ruby​​ on rails 上实现 postgresql 时出错

Question

在实现 rake db:migrate 时出现以下错误

rake aborted!
Please install the postgresql adapter: `gem install activerecord-postgresql-adapter` (pg is not part of the bundle. Add it to Gemfile.)

我使用 postgresql 在数据库中创建了两个表。

我的 database.yml 是

development:
  adapter: postgresql
  encoding: unicode
  host: localhost
  database: shop_development
  pool: 5
  username: postgres
  password: 

test:
  adapter: postgresql
  encoding: unicode
  host: localhost
  database: shop_test
  pool: 5
  username: postgres
  password: 

production:
  adapter: postgresql
  encoding: unicode
  host: localhost
  database: shop_production
  pool: 5
  username: postgres
  password: 

我也运行过如下命令：

C:\Sites\shop>gem install 'pg'
Successfully installed pg-0.14.1-x86-mingw32
1 gem installed
Installing ri documentation for pg-0.14.1-x86-mingw32...
Installing RDoc documentation for pg-0.14.1-x86-mingw32...

但这仍然给我同样的错误。

我的 gemfile 有以下内容：

GEM
  remote: https://rubygems.org/
  specs:
    actionmailer (3.2.11)
      actionpack (= 3.2.11)
      mail (~> 2.4.4)
    actionpack (3.2.11)
      activemodel (= 3.2.11)
      activesupport (= 3.2.11)
      builder (~> 3.0.0)
      erubis (~> 2.7.0)
      journey (~> 1.0.4)
      rack (~> 1.4.0)
      rack-cache (~> 1.2)
      rack-test (~> 0.6.1)
      sprockets (~> 2.2.1)
    activemodel (3.2.11)
      activesupport (= 3.2.11)
      builder (~> 3.0.0)
    activerecord (3.2.11)
      activemodel (= 3.2.11)
      activesupport (= 3.2.11)
      arel (~> 3.0.2)
      tzinfo (~> 0.3.29)
    activeresource (3.2.11)
      activemodel (= 3.2.11)
      activesupport (= 3.2.11)
    activesupport (3.2.11)
      i18n (~> 0.6)
      multi_json (~> 1.0)
    arel (3.0.2)
    builder (3.0.4)
    coffee-rails (3.2.2)
      coffee-script (>= 2.2.0)
      railties (~> 3.2.0)
    coffee-script (2.2.0)
      coffee-script-source
      execjs
    coffee-script-source (1.4.0)
    erubis (2.7.0)
    execjs (1.4.0)
      multi_json (~> 1.0)
    hike (1.2.1)
    i18n (0.6.1)
    journey (1.0.4)
    jquery-rails (2.2.1)
      railties (>= 3.0, < 5.0)
      thor (>= 0.14, < 2.0)
    json (1.7.6)
    mail (2.4.4)
      i18n (>= 0.4.0)
      mime-types (~> 1.16)
      treetop (~> 1.4.8)
    mime-types (1.21)
    multi_json (1.5.0)
    polyglot (0.3.3)
    rack (1.4.5)
    rack-cache (1.2)
      rack (>= 0.4)
    rack-ssl (1.3.3)
      rack
    rack-test (0.6.2)
      rack (>= 1.0)
    rails (3.2.11)
      actionmailer (= 3.2.11)
      actionpack (= 3.2.11)
      activerecord (= 3.2.11)
      activeresource (= 3.2.11)
      activesupport (= 3.2.11)
      bundler (~> 1.0)
      railties (= 3.2.11)
    railties (3.2.11)
      actionpack (= 3.2.11)
      activesupport (= 3.2.11)
      rack-ssl (~> 1.3.2)
      rake (>= 0.8.7)
      rdoc (~> 3.4)
      thor (>= 0.14.6, < 2.0)
    rake (10.0.3)
    rdoc (3.12.1)
      json (~> 1.4)
    sass (3.2.5)
    sass-rails (3.2.6)
      railties (~> 3.2.0)
      sass (>= 3.1.10)
      tilt (~> 1.3)
    sprockets (2.2.2)
      hike (~> 1.2)
      multi_json (~> 1.0)
      rack (~> 1.0)
      tilt (~> 1.1, != 1.3.0)
    sqlite3 (1.3.7-x86-mingw32)
    thor (0.17.0)
    tilt (1.3.3)
    treetop (1.4.12)
      polyglot
      polyglot (>= 0.3.1)
    tzinfo (0.3.35)
    uglifier (1.3.0)
      execjs (>= 0.3.0)
      multi_json (~> 1.0, >= 1.0.2)

PLATFORMS
  x86-mingw32

DEPENDENCIES
  coffee-rails (~> 3.2.1)
  jquery-rails
  rails (= 3.2.11)
  sass-rails (~> 3.2.3)
  sqlite3
  uglifier (>= 1.0.3)

我的 gemfile 有以下内容：-

source 'https://rubygems.org'

gem 'rails', '3.2.11'

# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'

# gem 'sqlite3'

 gem 'pg'


# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'

  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  # gem 'therubyracer', :platforms => :ruby

  gem 'uglifier', '>= 1.0.3'
end

gem 'jquery-rails'

# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'

# To use Jbuilder templates for JSON
# gem 'jbuilder'

# Use unicorn as the app server
# gem 'unicorn'

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'debugger'

我的捆绑安装显示以下内容：-

C:\Sites\shop>bundle install
Using rake (10.0.3)
Using i18n (0.6.1)
Using multi_json (1.5.0)
Using activesupport (3.2.11)
Using builder (3.0.4)
Using activemodel (3.2.11)
Using erubis (2.7.0)
Using journey (1.0.4)
Using rack (1.4.5)
Using rack-cache (1.2)
Using rack-test (0.6.2)
Using hike (1.2.1)
Using tilt (1.3.3)
Using sprockets (2.2.2)
Using actionpack (3.2.11)
Using mime-types (1.21)
Using polyglot (0.3.3)
Using treetop (1.4.12)
Using mail (2.4.4)
Using actionmailer (3.2.11)
Using arel (3.0.2)
Using tzinfo (0.3.35)
Using activerecord (3.2.11)
Using activeresource (3.2.11)
Using bundler (1.0.22)
Using coffee-script-source (1.4.0)
Using execjs (1.4.0)
Using coffee-script (2.2.0)
Using rack-ssl (1.3.3)
Using json (1.7.6)
Using rdoc (3.12.1)
Using thor (0.17.0)
Using railties (3.2.11)
Using coffee-rails (3.2.2)
Using jquery-rails (2.2.1)
Using pg (0.14.1)
Using rails (3.2.11)
Using sass (3.2.5)
Using sass-rails (3.2.6)
Using uglifier (1.3.0)
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem
is installed.

Answer 1

请试试这个..

 sudo apt-get install postgresql postgresql-client postgresql-contriblibpq-dev

Answer 2

你跑bundle install了吗？
看起来当前已安装 sqlite3，但未安装 pg。

如果您要将数据从 sqlite3 移动到 pg，请查看此 railscast：Migrating to PostgreSQL