Rails gives NameError for all command line methods such as generate or rake

问题

I'm a beginner with Rails and I've been trying to find out what in the world is going wrong here for the past few days but with absolutely no luck. I searched everywhere, but found nothing. Basically, when I run any sort of command line method, I will get a NameError. I have tried running this in different project directories as well that used to work. It seems that rails is just broken...

I am running Win7-32bit using NetBeans 6.9.1 for editing files and cmd.exe for running rails console.

Everything had been working fine for about two weeks and then this started happening suddenly. Here are a few examples:

rails generate model:

irb(main):004:0> rails generate model datatest  
NameError: undefined local variable or method `datatest' for main:Object  
from (irb):4  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:44:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:8:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands.rb:23:in `<top (required)>'  
from script/rails:6:in `require'  
from script/rails:6:in `<main>' 

rails generate migration:

irb(main):003:0> rails generate migration rename_password_to_hashed_password  
NameError: undefined local variable or method `rename_password_to_hashed_password' for main:Object  
from (irb):3  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:44:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:8:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands.rb:23:in `<top (required)>'  
from script/rails:6:in `require'  
from script/rails:6:in `<main>' 

rake db:migrate:

irb(main):005:0> rake db:migrate  
NameError: undefined local variable or method `migrate' for main:Object  
from (irb):5  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:44:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands/console.rb:8:in `start'  
from C:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/commands.rb:23:in `<top (required)>'  
from script/rails:6:in `require'  
from script/rails:6:in `<main>' 

Any sort of help would be VERY appreciated. Thanks!

回答1:

These commands don't work from within irb, you have to start them directly from cmd.exe.

回答2:

I would take the initiative of elaborating @dhofset's answer. Basically we use rails app related commands in the console directly and not in the irb console. Even I work on windows so I give you this with few examples

This is what you do

1. Create new App
C:\Users\rohit>rails new_app

2. Generate a scaffold
C:\Users\rohit\new_app>ruby script\generate scaffold User name:string

3. Generate a model
C:\Users\rohit\new_app>ruby script\generate model User name:string

4. To run a rake task
C:\Users\rohit\new_app>rake db:create
C:\Users\rohit\new_app>rake db:migrate

Hope you have a better understanding now.

回答3:

Yep, dhofstet has it right: these are all commands for the windows prompt, they're not ruby statements.

来源：https://stackoverflow.com/questions/4395222/rails-gives-nameerror-for-all-command-line-methods-such-as-generate-or-rake