耙db：迁移不为我工作
我收到这个错误
rake db:migrate (in /Users/john/Sites/my_app) rake aborted! Don't know how to build task 'db:migrate'
当我追踪我得到的错误时
rake aborted! Don't know how to build task 'db:migrate' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1728:in `[]' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2050:in `invoke_task' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31 /usr/local/bin/rake:19:in `load' /usr/local/bin/rake:19
我的Rakefile是
require(File.join(File.dirname(__FILE__), 'config', 'boot'))
require 'rake'
require 'rake/testtask'
require 'rake/rdoctask'
对于Ruby on Rails 2.3，您应该在Rakefile的末尾添加以下行：
require 'tasks/rails'