从pq切换到sqlite3 ruby​​ on rails

Question

我试图从pg更改为sqlite3后出现错误。

rake db:reset 
rake aborted! 
Gem::LoadError: Specified 'postgresql' for database adapter, but the gem is not loaded. Add `gem 'pg'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord). 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/connection_specification.rb:177:in `rescue in spec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/connection_specification.rb:174:in `spec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_handling.rb:50:in `establish_connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railtie.rb:120:in `block (2 levels) in <class:Railtie>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:27:in `each' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:27:in `on_load' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railtie.rb:116:in `block in <class:Railtie>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `instance_exec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `run' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:55:in `block in run_initializers' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:54:in `run_initializers' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:352:in `initialize!' 
/home/ubuntu/workspace/config/environment.rb:5:in `<top (required)>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:328:in `require_environment!' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:457:in `block in run_tasks_blocks' 
/usr/local/rvm/gems/ruby-2.3.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>' 
/usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval' 
/usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>' 
Gem::LoadError: pg is not part of the bundle. Add it to your Gemfile. 
/usr/local/rvm/gems/ruby-2.3.0/gems/bundler-1.15.1/lib/bundler/rubygems_integration.rb:377:in `block (2 levels) in replace_gem' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb:16:in `<top (required)>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/connection_specification.rb:175:in `spec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_handling.rb:50:in `establish_connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railtie.rb:120:in `block (2 levels) in <class:Railtie>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:27:in `each' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/lazy_load_hooks.rb:27:in `on_load' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railtie.rb:116:in `block in <class:Railtie>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `instance_exec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:30:in `run' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:55:in `block in run_initializers' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/initializable.rb:54:in `run_initializers' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:352:in `initialize!' 
/home/ubuntu/workspace/config/environment.rb:5:in `<top (required)>' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:328:in `require_environment!' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/application.rb:457:in `block in run_tasks_blocks' 
/usr/local/rvm/gems/ruby-2.3.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>' 
/usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval' 
/usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>' 
Tasks: TOP => db:reset => environment 
(See full trace by running task with --trace) 

现在我知道，ActiveRecord的告诉我添加PG宝石，但我的机器是在具有运行PQ服务器（而不是为生产和固定它的错误，我试图把源码的懒惰在产品上发现并保留pg）

有关如何解决此问题的任何提示？

Answer 1

请尝试将adapter的config/database.yml从postgresql更改为sqlite3。

它应该有所帮助。