Intalling the PostgreSQL gem pq for Heroku

Question

这里的第一个问题，但是我现在要非常感谢您，因为Stackoverflow在Michael Hartl Tut的第一章中帮助了我将近15次。

现在，我正在尝试使用此命令安装PostgreSQL（PG GEM）：

`

    group :production do 
     gem 'pg', '0.15.1'
     gem 'rails_12factor', '0.0.2'
   end`

但显示出错误

-bash: group: command not found

然后我尝试直接安装

的宝石

gem install pg

，但它显示了另一个错误

`Fetching: pg-0.17.1.gem (100%) 

Building native extensions.  This could take a while... 


 ERROR:  Error installing pg:
        ERROR: Failed to build gem native extension.

rvm/rubies/ruby-2.0.0-p353/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 more details.  You may
need configuration options.
Provided configuration options:

--with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/Users/trabalho/.rvm/rubies/ruby-2.0.0-p353/bin/ruby
    --with-pg
    --without-pg
    --with-pg-config
    --without-pg-config
    --with-pg_config
    --without-pg_config
    --with-pg-dir
    --without-pg-dir
    --with-pg-include
    --without-pg-include=${pg-dir}/include
    --with-pg-lib
    --without-pg-lib=${pg-dir}/
extconf failed, exit code 1
Gem files will remain installed in .rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/pg-0.17.1 for inspection.
Results logged to .rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/extensions/x86_64-darwin-10/2.0.0/pg-0.17.1/gem_make.out`

我不明白它是否已安装，我也无法确认。如何使组命令工作？还是如何安装GEM PG和Rails_12Factor？有帮助吗？

Answer 1

您是否正在运行Ubuntu？看起来您需要此库：

sudo apt-get install libpq-dev

源

Answer 2

您不想将group ...作为终端中的命令运行，而是将代码块放入Rails应用程序的Gemfile中。

gemfile

group :production do 
  gem 'pg', '0.15.1'
  gem 'rails_12factor', '0.0.2'
end

然后运行bundle命令。

如果您仍然无法以这种方式编译pg GEM，则需要确保已安装XCode命令行工具（假设您正在使用OSX）。要安装这些只是从您的终端运行xcode-select --install并按照提示。

Answer 3

sudo apt-get install libpq-dev 

它在Ubuntu上帮助了我