rake db 问题：迁移 -

Question

我无法为 Ruby on Rails 设置 MySQL 数据库。设置数据库并确保 config/database.yml 文件匹配后，我遇到了以下错误消息。

U:\Rails\alpha>rake db:migrate --trace
(in U:/Rails/alpha)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
rake aborted!
Access denied for user 'admin'@'207-237-91-100.c3-0.avec-ubr13.nyr-avec.n
y.cable.rcn.com' (using password: YES)
C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.6-x86-mingw32/lib/mysql2/client.rb:
37:in `connect'
C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.6-x86-mingw32/lib/mysql2/client.rb:
37:in `initialize'
C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.6-x86-mingw32/lib/active_record/con
nection_adapters/mysql2_adapter.rb:14:in `new'
C:/Ruby187/lib/ruby/gems/1.8/gems/mysql2-0.2.6-x86-mingw32/lib/active_record/con
nection_adapters/mysql2_adapter.rb:14:in `mysql2_connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:230:in `send'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:230:in `new_connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:238:in `checkout_new_connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:194:in `checkout'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:190:in `loop'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:190:in `checkout'
C:/Ruby187/lib/ruby/1.8/monitor.rb:242:in `synchronize'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:189:in `checkout'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:96:in `connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_pool.rb:318:in `retrieve_connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_specification.rb:97:in `retrieve_connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/connectio
n_adapters/abstract/connection_specification.rb:89:in `connection'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/migration
.rb:486:in `initialize'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/migration
.rb:433:in `new'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/migration
.rb:433:in `up'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/migration
.rb:415:in `migrate'
C:/Ruby187/lib/ruby/gems/1.8/gems/activerecord-3.0.1/lib/active_record/railties/
databases.rake:142
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_cal
l_chain'
C:/Ruby187/lib/ruby/1.8/monitor.rb:242:in `synchronize'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_cal
l_chain'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_excep
tion_handling'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_excep
tion_handling'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
C:/Ruby187/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31
C:/Ruby187/bin/rake:19:in `load'
C:/Ruby187/bin/rake:19

我已经检查了密码大约 15 次以上，据我所知它是正确的。

database.yml 文件：

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: dbname
  pool: 5
  username: admin
  password: pwhere
  host: sql.domain.com

谢谢

Answer 1

测试这一点的一种方法是从 Rails 所在的机器上的命令行连接到 mysql。 像您这样的人

mysql -u admin -ppwhere -h sql.domain.com

可能会发现您也无法以这种方式连接。如果是这样，您可能遇到了 GRANT 问题，这可能是由于在 GRANT 中指定了错误的主机所致。例如，如果数据库和rails驻留在同一台机器上，mysql可能会认为您是从“localhost”连接，而不是rails框的DNS名称（反之亦然）。

一开始，您可能只想授予管理员用户访问所有内容的权限：

GRANT ALL ON *.* to 'admin'@'whereever_rails_lives' IDENTIFIED BY 'pwhere'

mysql grant 语法

诀窍通常是让“whereever_rails_lives”正确。

Answer 2

您的权限不正确。这是一个蹩脚的错误，因为它实际上意味着两件事。 1) 您的密码/用户名组合错误；另外，你无法连接到 mysql，这可能严重意味着连接到 gem 问题、安装问题。 Mysql 可能会变得很挑剔！

从你的问题来看，我了解到你对这一切都很陌生。我建议不要担心连接到 MySQL，而是从 sqlite 开始。您不需要全文搜索和 lite 不提供的其他功能！

那么，让我们开始使用 sqlite3。如何？

这样工作量就少了只需制作一个 Rails 应用程序，然后 rake db:create 即可完成。那么当你需要mysql数据库的功能时，根据你对Rails的熟悉和调试，你就可以真正知道错误是怎么回事。