Question

这是我第一次尝试在rails上使用MySql。使用sqlite3也会发生这种情况，除非它指向我做'gem install activerecord-sqlite3-adapter`，告诉我没有这样的宝石命名它。

我正在使用最新的Ruby 2.0。我正在使用最新的Rails 3.2.13 我有mysql2（0.3.11）宝石我也有activerecord-mysql2-adapter（0.0.3）

然而......它给了我以下信息：

C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/rubygems_integration.rb:214:in 'block in replace_gem': Please install the mysql2 adapter: 'gem install activerecord-mysql2-adapter' (mysql2 is not part of the bundle. Add it to Gemfile.) (LoadError)

当我执行rails new [project name]

时，捆绑程序运行了

如果是mysql2 gem的错误，则此命令在64位Windows系统上成功安装mysql2：gem install mysql2 -v '0.3.11' -- '--with-mysql-lib="C:\MySQL\lib" --with-mysql-include="C:\MySQL\include"'

生成的Gemfile正在使用gem 'mysql2'确定，正如我所知道的那样正常。

Database.yml如下：

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: shop_development
  pool: 5
  username: charlie
  password: *******
  host: localhost

我手动创建了一个名为[projectname] _development的数据库。

C:\Users\Charlie\Documents\RailsProject\demo_app>rails s
=> Booting WEBrick
=> Rails 3.2.13 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/bundler-1.3.5/lib/bundler/rubygems_integ
ration.rb:214:in `block in replace_gem': Please install the mysql2 adapter: `gem
 install activerecord-mysql2-adapter` (mysql2 is not part of the bundle. Add it
to Gemfile.) (LoadError)
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/connection_adapters/mysql2_adapter.rb:3:in `<top (required)>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/dependencies.rb:251:in `require'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/dependencies.rb:251:in `block in require'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/dependencies.rb:236:in `load_dependency'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/dependencies.rb:251:in `require'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/connection_adapters/abstract/connection_specification.rb:50:in `resol
ve_hash_connection'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/connection_adapters/abstract/connection_specification.rb:41:in `resol
ve_string_connection'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'

        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/connection_adapters/abstract/connection_specification.rb:130:in `esta
blish_connection'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/railtie.rb:82:in `block (2 levels) in <class:Railtie>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/lazy_load_hooks.rb:36:in `instance_eval'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/lazy_load_hooks.rb:36:in `execute_hook'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/lazy_load_hooks.rb:43:in `block in run_load_hooks'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/lazy_load_hooks.rb:42:in `each'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activesupport-3.2.13/lib/ac
tive_support/lazy_load_hooks.rb:42:in `run_load_hooks'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/base.rb:720:in `<top (required)>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/activerecord-3.2.13/lib/act
ive_record/railtie.rb:88:in `block in <class:Railtie>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/i
nitializable.rb:30:in `instance_exec'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/i
nitializable.rb:30:in `run'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/i
nitializable.rb:55:in `block in run_initializers'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/i
nitializable.rb:54:in `each'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/i
nitializable.rb:54:in `run_initializers'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/a
pplication.rb:136:in `initialize!'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/r
ailtie/configurable.rb:30:in `method_missing'
        from C:/Users/Charlie/Documents/RailsProject/demo_app/config/environment
.rb:5:in `<top (required)>'
        from C:/Users/Charlie/Documents/RailsProject/demo_app/config.ru:3:in `re
quire'
        from C:/Users/Charlie/Documents/RailsProject/demo_app/config.ru:3:in `bl
ock in <main>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/builder
.rb:51:in `instance_eval'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/builder
.rb:51:in `initialize'
        from C:/Users/Charlie/Documents/RailsProject/demo_app/config.ru:in `new'

        from C:/Users/Charlie/Documents/RailsProject/demo_app/config.ru:in `<mai
n>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/builder
.rb:40:in `eval'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/builder
.rb:40:in `parse_file'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/server.
rb:200:in `app'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/c
ommands/server.rb:46:in `app'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/server.
rb:304:in `wrapped_app'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/rack-1.4.5/lib/rack/server.
rb:254:in `start'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/c
ommands/server.rb:70:in `start'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/c
ommands.rb:55:in `block in <top (required)>'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/c
ommands.rb:50:in `tap'
        from C:/Ruby200-x64/lib/ruby/gems/2.0.0/gems/railties-3.2.13/lib/rails/c
ommands.rb:50:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

Answer 1

检查以下内容

您的Gemfile是否有条目gem 'mysql2'？
运行$ bundle update命令时会发生什么？任何错误
您可以尝试使用以下命令生成应用

rails new demo_app -d mysql

尝试上述应用时会出现什么错误？

Rails服务器无法使用mysql2启动 - 它需要的Gems存在

1 个答案: