在 Rails 上从 pq 切换到 sqlite3 ruby

Question

尝试从 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 告诉我添加 PG gem，但我的机器在运行 pq 服务器时出错（而不是高效并修复它，我懒惰地尝试将 sqlite 放在 deve 上并保持 pg在产品上）

关于如何解决这个问题的任何提示？

Answer 1

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

应该有帮助。