在我的计算机上的每个Rails项目上，由于我重新安装了它，我无法进行任何迁移：当我在终端中输入rake db:migrate时没有任何反应
$ my_project ➜ rails g migration fake_migration
invoke active_record
create db/migrate/20140806092408_fake_migration.rb
$ my_project ➜ rake db:migrate:status
database: /Users/me/Documents/my_project/db/development.sqlite3
Status Migration ID Migration Name
--------------------------------------------------
down 20140806092408 Fake migration
$ my_project ➜ rake db:migrate
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:migrate
** Invoke db:_dump (first_time)
** Execute db:_dump
** Invoke db:schema:dump (first_time)
** Invoke environment
** Invoke db:load_config
** Execute db:schema:dump
$ my_project ➜ rake db:migrate:status
database: /Users/me/Documents/my_project/db/development.sqlite3
Status Migration ID Migration Name
--------------------------------------------------
down 20140806092408 Fake migration
当我尝试手动迁移时（如评论中所示）：
$ my_project ➜ rake db:migrate:up VERSION=20140806092408 --trace
rake aborted!
ActiveRecord::UnknownMigrationVersionError:
No migration with version number 20140806092408
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activerecord-4.1.4/lib/active_record/migration.rb:933:in `run'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activerecord-4.1.4/lib/active_record/migration.rb:818:in `run'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:71:in `block (3 levels) in <top (required)>'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/Users/me/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/Users/me/.rbenv/versions/2.1.2/bin/rake:23:in `load'
/Users/me/.rbenv/versions/2.1.2/bin/rake:23:in `<main>'
Tasks: TOP => db:migrate:up
答案 0 :(得分：8)
如果有人遇到此问题，请留意您的环境变量。如果您定义了名为＆＃34; VERSION＆＃34;的env var，它将阻止迁移任务。
我使用dotenv gem来管理railsn的本地开发环境变量，当我删除一个名为VERSION的var（我创建它来管理API版本）时，迁移按预期工作。
答案 1 :(得分：0)
似乎迁移文件已丢失/删除，因为迁移ID显示为000而不是时间戳。时间戳是唯一的。重新生成迁移，然后rake db：migrate。
答案 2 :(得分：0)
使用 Vagrant 代替本地安装解决了问题。 不知道问题出在哪里，可能与Mac OS X有关。