数据库迁移问题

Question

我刚刚使用rake db:migrate通过应用程序和数据库进行了更新。但是，我遇到了一个错误：

Migrating to CreateSavedBoards (20110111184104)
==  CreateSavedBoards: migrating ==============================================
-- drop_table(:boards)
  SQL (0.0ms)   Mysql::Error: Unknown table 'boards': DROP TABLE `boards`
rake aborted!
An error has occurred, all later migrations canceled:

Mysql::Error: Unknown table 'boards': DROP TABLE `boards`

(See full trace by running task with --trace)

迁移文件是否导致错误？

class CreateBoardCategoriesSavedboards < ActiveRecord::Migration
  def self.up
    create_table :board_categories_boards, :id => false do |t|
      t.integer :board_category_id
      t.integer :board_id
    end

    add_index :board_categories_boards, [:board_category_id, :board_id], :name => "bcb_board_category_id_board_id"
  end

  def self.down
    drop_table :board_categories_boards
  end
end

这是电路板的模型。

class Board < ActiveRecord::Base
  belongs_to :image, :foreign_key => 'image'
  belongs_to :clip, :foreign_key => 'clip'
  has_and_belongs_to_many :categories, :class_name => 'BoardCategory', :foreign_key => 'board_id'
  has_many :comments, :as => :commentable
  set_table_name "savedboards"
end

我认为错误来自Rails，因为上面的迁移文件中的board_id认为有一个boards表。

我认为这可能会导致迁移失败，我能做些什么？

Answer 1

迁移的输出显示drop_table :boards正在发生，但它没有出现在您的迁移中。也许是较早的迁移尝试删除boards表？