当我运行rake:db migrate命令时出现错误"未初始化的常量CreateArticles"

我创建了一个模型ruby脚本/生成模型文章(简单enuff)

这是迁移文件create_articles.rb:

def self.up
  create_table :articles do |t|
    t.column :user_id, :integer
    t.column :title, :string
    t.column :synopsis, :text, :limit => 1000
    t.column :body, :text, :limit => 20000
    t.column :published, :boolean, :default => false
    t.column :created_at, :datetime
    t.column :updated_at, :datetime
    t.column :published_at, :datetime
    t.column :category_id, :integer
  end

def self.down
  drop_table :articles
 end
end

当我运行rake:db migrate命令时,我收到一个错误rake中止!"未初始化的常量CreateArticles."

有谁知道为什么这个错误不断发生？

确保你的文件名和类名说的相同(除了类名是驼峰).迁移文件的内容应该类似于这样,简化它们:

#20090106022023_create_articles.rb
class CreateArticles < ActiveRecord::Migration   
  def self.up
    create_table :articles do |t|
      t.belongs_to :user, :category
      t.string :title
      t.text :synopsis, :limit => 1000
      t.text :body, :limit => 20000
      t.boolean :published, :default => false
      t.datetime :published_at
      t.timestamps
    end
  end

  def self.down
    drop_table :articles
  end
end