Question

我正在使用 MySQL Server 5.7 ，在 Windows 7 64 上通过Lynda.com完成教程 Ruby on Rails 3 Essential Training > MySQL Connector C 6.1 6.1.2 ， Ruby 1.9.3p392（2013-02-22）[i386-mingw32] 和 Rails 4.0.2 。

在培训中，我在“数据库和迁移”部分尝试将我在MySQL中创建的数据库与我的Rails项目同步，但是我一直在遇到中止消息。

教师要求我的班级通过命令提示符打开我们的rails项目并执行Rake以使用以下代码构建“schema.rb”：

$ rake db：schema：dump

每次我输入以下代码时，这个中止消息就是结果：

C：\ Users \ User \ Documents \ simple_cms＆gt; rake db：schema：dump

rake aborted！

不知道如何构建任务'db：schema：dump'

（通过使用--trace运行任务查看完整跟踪）

我花了最后24小时卸载，下载和重新安装多个版本的Ruby，Rails，MySQL服务器和连接器，花费了我最长的时间用于学习如何添加安装MySQL2 gem我通过下载完成旧版本 mysql 0.2.6 。

尽管如此，该中止消息仍保持不变。

此外，当我在此处输入rake -T时，没有数据库耙子显示：

rake about

rake assets：clean [keep]

rake assets：clobber

rake assets：environment

rake assets：precompile

rake cache_digests：dependencies

rake cache_digests：nested_dependencies

（db应显示但不显示）

rake doc：app

...

rake test：all：db

...

rake tmp：create

帮助吗 的

按要求提供Gem文件

source '...'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.0.2'

# Use mysql as the database for Active Record
gem 'mysql2'

# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.0'

# 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 ... 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. Read more: ...
gem 'turbolinks'

# Build JSON APIs with ease. Read more: ...
gem 'jbuilder', '~> 1.2'

group :doc do
  # bundle exec rake doc:rails generates the API under doc/api.
  gem 'sdoc', require: false
end

# Use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.1.2'

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

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

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

Answer 1

在文件database.yml中，你应该有：

default: &default
  adapter: mysql2
  encoding: utf8
  database: simple_cms_development
  pool: 5
  username: simple_cms
  password: secretpassword
  socket: /tmp/mysql.sock

development:
  <<: *default
  database: simple_cms_development

您应该检查在实际环境中是否正确定义了database（development）。

评论：您没有db: rake -T命令，因此问题出在其他地方。

Answer 2

您将收到此错误

~/Project$ rake db:schema:dump
rake aborted!
Don't know how to build task 'db:schema:dump'
(See full trace by running task with --trace)

因为您的rails应用程序中不包含active_record

将以下行添加到application.rb

require "active_record/railtie"

现在试试，

~/Project$ rake -T

您应该能够看到rake db命令

$ rails -T
rails about                              # List versions of all Rails frameworks and the environment
rails assets:clean[keep]                 # Remove old compiled assets
rails assets:clobber                     # Remove compiled assets
rails assets:environment                 # Load asset compile environment
rails assets:precompile                  # Compile all the assets named in config.assets.precompile
rails cache_digests:dependencies         # Lookup first-level dependencies for TEMPLATE (like messages/show or comments/_com...
rails cache_digests:nested_dependencies  # Lookup nested dependencies for TEMPLATE (like messages/show or comments/_comment....
rails db:create                          # Creates the database from DATABASE_URL or config/database.yml for the current RAI...
rails db:drop                            # Drops the database from DATABASE_URL or config/database.yml for the current RAILS...
rails db:environment:set                 # Set the environment value for the database
rails db:fixtures:load                   # Loads fixtures into the current environment's database
rails db:migrate                         # Migrate the database (options: VERSION=x, VERBOSE=false, SCOPE=blog)
rails db:migrate:status                  # Display status of migrations
rails db:rollback                        # Rolls the schema back to the previous version (specify steps w/ STEP=n)
rails db:schema:cache:clear              # Clears a db/schema_cache.dump file
rails db:schema:cache:dump               # Creates a db/schema_cache.dump file
rails db:schema:dump                     # Creates a db/schema.rb file that is portable against any DB supported by Active R...
rails db:schema:load                     # Loads a schema.rb file into the database
rails db:seed                            # Loads the seed data from db/seeds.rb
rails db:setup                           # Creates the databa

Rake Aborted：db：schema：dump

2 个答案: