数据库迁移问题

Question

我刚刚通过应用程序和db使用rake db:migrate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 

这是委员会的模型。

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 

我想到的是，错误来自Rails的思维，有一个boards表，因为在上面的迁移文件的board_id。

我是否认为这可能会导致迁移失败，我该怎么办？

Answer 1

该迁移的输出显示drop_table :boards正在发生，但它未显示在您的迁移中。也许这是一个早期的迁移，试图删除boards表？