PG :: UndefinedColumn：错误：关系“articles”的列“image_file_name”不存在

Question

有人可以帮我运行heroku run db:migrate吗？我已经忘记在heroku上运行db：migration和dev env上的迁移。我做了他们的coulple，现在我收到以下错误：

wozane:~/workspace (master) $ heroku run rake db:migrate       
Running rake db:migrate on ⬢ wozane... up, run.7786 
    (0.8ms) SELECT pg_try_advisory_lock(96974639112725850); 
    ActiveRecord::SchemaMigration Load (1.1ms) SELECT "schema_migrations".* FROM "schema_migrations" 
Migrating to RemoveColumnImage (20160917131520) 
    (0.7ms) BEGIN 
== 20160917131520 RemoveColumnImage: migrating ================================ 
-- remove_column(:articles, :image_file_name, :string) 
    (1.5ms) ALTER TABLE "articles" DROP "image_file_name" 
    (0.7ms) ROLLBACK 
    (0.8ms) SELECT pg_advisory_unlock(96974639112725850) 
rake aborted! 
StandardError: An error has occurred, this and all later migrations canceled: 

PG::UndefinedColumn: ERROR: column "image_file_name" of relation "articles" does not exist 
: ALTER TABLE "articles" DROP "image_file_name" 

这种情况是，此列已被删除，它不存在。

迁移错误消息中提到（编号20160917131520）：

class RemoveColumnImage < ActiveRecord::Migration[5.0] 
    def change 
    remove_column :articles, :image_file_name , :string 
    remove_column :articles, :image_content_type, :string 
    remove_column :articles, :image_file_size, :integer 
    remove_column :articles, :image_updated_at, :datetime 
    end 
end 

Schema.rb看起来像这样：

ActiveRecord::Schema.define(version: 20160921115118) do 

    create_table "articles", force: :cascade do |t| 
    t.string "title" 
    t.text  "text" 
    t.datetime "created_at", null: false 
    t.datetime "updated_at", null: false 
    t.string "img_url" 
    end 

    create_table "photos", force: :cascade do |t| 
    t.datetime "created_at", null: false 
    t.datetime "updated_at", null: false 
    t.string "title" 
    t.string "img_url" 
    t.text  "text" 
    end 

end 

我试图#迁移整个代码，并没有帮助以及那些没有工作的评论：

rails db:environment:set RAILS_ENV=production 
heroku run rake db:reset 
heroku run rake db:migrate -app wozane 
heroku pg:reset DATABASE --confirm wozane 

做任何人有一个想法如何在我的情况下运行heroku迁移？

在此先感谢。

Answer 1

只是注释掉删除列迁移的代码。

class RemoveColumnImage < ActiveRecord::Migration[5.0] 
    def change 
    #remove_column :articles, :image_file_name , :string 
    #remove_column :articles, :image_content_type, :string 
    #remove_column :articles, :image_file_size, :integer 
    #remove_column :articles, :image_updated_at, :datetime 
    end 
end 

，并尝试运行heroku run rake db:migrate -app wozane