ruby-on-rails - Rails g 迁移不起作用

Question

当我运行命令时

rails g migration migration_name

我会收到“错误”信息:

Usage:
  rails new APP_PATH [options]

Options:
  -r, [--ruby=PATH]              # Path to the Ruby binary of your choice
                                 # Default: /Users/radek/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
  -b, [--builder=BUILDER]        # Path to a application builder (can be a filesystem path or URL)
  -m, [--template=TEMPLATE]      # Path to an application template (can be a filesystem path or URL)
      [--skip-gemfile]           # Don't create a Gemfile
      [--skip-bundle]            # Don't run bundle install
  -G, [--skip-git]               # Skip Git ignores and keeps
  -O, [--skip-active-record]     # Skip Active Record files
  -S, [--skip-sprockets]         # Skip Sprockets files
  -d, [--database=DATABASE]      # Preconfigure for selected database (options: mysql/oracle/postgresql/sqlite3/frontbase/ibm_db/sqlserver/jdbcmysql/jdbcsqlite3/jdbcpostgresql/jdbc)
                                 # Default: sqlite3
  -j, [--javascript=JAVASCRIPT]  # Preconfigure for selected JavaScript library
                                 # Default: jquery
  -J, [--skip-javascript]        # Skip JavaScript files
      [--dev]                    # Setup the application with Gemfile pointing to your Rails checkout
      [--edge]                   # Setup the application with Gemfile pointing to Rails repository
  -T, [--skip-test-unit]         # Skip Test::Unit files
      [--old-style-hash]         # Force using old style hash (:foo => 'bar') on Ruby >= 1.9

Runtime options:
  -f, [--force]    # Overwrite files that already exist
  -p, [--pretend]  # Run but do not make any changes
  -q, [--quiet]    # Suppress status output
  -s, [--skip]     # Skip files that already exist

Rails options:
  -h, [--help]     # Show this help message and quit
  -v, [--version]  # Show Rails version number and quit

Description:
    The 'rails new' command creates a new Rails application with a default
    directory structure and configuration at the path you specify.

    You can specify extra command-line arguments to be used every time
    'rails new' runs in the .railsrc configuration file in your home directory.

    Note that the arguments specified in the .railsrc file don't affect the
    defaults values shown above in this help message.

Example:
    rails new ~/Code/Ruby/weblog

    This generates a skeletal Rails installation in ~/Code/Ruby/weblog.
    See the README in the newly created application to get going.

第一次收到这样的消息。在其他项目中，此命令运行良好，但在这里我仍然收到此消息...

是什么原因造成的？我错过了什么吗？(是的，我在各自项目的根目录下)

Answer 1

您没有在 Rails 生成的项目目录中运行它。你在它外面运行它。

编辑:也可能是缺少脚本文件夹。或者，如果您在项目文件夹中执行 Rails 脚本，则脚本文件夹中缺少 Rails 脚本。