Question

我正在尝试将PostgreSQL而不是SQLite3用于我的Rails应用程序，因为Heroku需要PostgreSQL，我想部署应用程序。使用Postgres标志启动我的应用程序（即--databse=postgresql）工作正常。但是，在将gem twitter-boostrap-rails添加到Gemfile并运行bundle install后，我收到有关SQLite3的错误：

active_record/connection_adapters/connection_specification.rb:190:in
rescue in spec': Specified 'sqlite3' for database adapter, but the gem is not loaded. Add gem'sqlite3'`到您的Gemfile（并确保它的版本是ActiveRecord所要求的最低值）

这是我的Gemfile：

source 'https://rubygems.org'

gem "therubyracer"
gem "less-rails"
gem "twitter-bootstrap-rails"


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.1.4'
# Use postgresql as the database for Active Record
gem 'pg'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.3'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer',  platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster.              
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0',          group: :doc

# Spring speeds up development by keeping your application running in the background.   
gem 'spring',        group: :development

# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

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

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

# Use debugger
# gem 'debugger', group: [:development, :test]

gem 'rails_12factor', group: :production>

这是我的database.yml：

----------


# PostgreSQL. Versions 8.2 and up are supported.
#
# Install the pg driver:
#   gem install pg
# On OS X with Homebrew:
#   gem install pg -- --with-pg-config=/usr/local/bin/pg_config
# On OS X with MacPorts:
#   gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
# On Windows:
#   gem install pg
#       Choose the win32 build.
#       Install PostgreSQL and put its /bin directory on your path.
#
# Configure Using Gemfile
# gem 'pg'
#
default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see rails configuration guide
  # http://guides.rubyonrails.org/configuring.html#database-pooling
  pool: 5

development:
  <<: *default

为什么我收到此错误，如何解决问题？

Answer 1

尝试设置数据库配置以进行开发显式。看起来database.yml没有正确对齐。

development:
  adapter: postgresql
  encoding: utf8
  database: your_db
  host: 127.0.0.1
  pool: 5
  username: your_db_username
  password: your_db_password

Answer 2

尝试运行bundle update然后bundle exec rails s - 您还需要在您的database.yml中指定更多参数，例如您的主机等，应该看起来像这样：

development:
  adapter: postgresql
  encoding: unicode
  database: some_database_name
  pool: 5
  host: localhost
  username: your_username (or root) if just dev
  password: your_password

请记住，因为这都是开发人员，用户名/ pw的安全性并不重要，因为它不包含任何重要数据/无法在您的计算机外访问

使用PostgreSQL时Rails会出错

2 个答案: