Rake:不知道如何构建任务'db :: create'

Question

我想学习Ruby on Rails并建立一个测试环境.

我使用"rails new Lab"创建了一个新的rails应用程序

然后我陷入了使用"rake db :: create"创建数据库的困境:

henke@ubuntu:~/Rails Projects/Lab$ rake db::create --trace
(in /home/henke/Rails Projects/Lab)
rake aborted!
Don't know how to build task 'db::create'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:1728:in `[]'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2050:in `invoke_task'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2029:in `block (2 levels) in top_level'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2029:in `block in top_level'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2001:in `block in run'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
/home/henke/.rvm/gems/ruby-1.9.2-p180/gems/rake-0.8.7/bin/rake:31:in `<top (required)>'
/home/henke/.rvm/gems/ruby-1.9.2-p180/bin/rake:19:in `load'
/home/henke/.rvm/gems/ruby-1.9.2-p180/bin/rake:19:in `<main>'

我也试过使用"rake db :: migrate",同样的错误.当我查看"rake -T"时,"db :: create"和"db :: migrate"都会出现在列表中.

我的环境:

• Ubuntu 10.10
• Ruby 1.9.2(在我的主目录中使用RVM)
• Rails 3.0.5
• sqlite3-1.3.3

有任何想法吗？如果您需要更多信息,请告诉我们!

Answer 1

使用单个冒号:

rake db:create

作为旁注,请避免使用*nix中的文件夹和文件名称中的空格.虽然它可能主要起作用,但有时某些程序会绊倒并且可能让你想知道"为什么这不起作用".