Ruby on rails Rails迁移问题

我试图启动并运行一个应用程序，但在运行rake db:migrate时遇到了这个问题：

AddDueDateToProjectTodos: migrating =======================================
-- add_column(:project_todos, :due_date, :string)
rake aborted!
An error has occurred, this and all later migrations canceled:

SQLite3::SQLException: no such table: project_todos: ALTER TABLE "project_todos" ADD "due_date" varchar(255)

我认为这可能是由于开发人员删除了迁移，因为他说他以前做过迁移

是否有任何方法可以解决此问题，或者我是否需要重新创建迁移？如果是这样的话，解决这个问题最好的办法是什么

编辑

这是database.yml文件

# development:
#   adapter: sqlite3
#   encoding: utf8
#   database: subscriptions_development
#   username: root
#   password:
# 
# # Warning: The database defined as 'test' will be erased and
# # re-generated from your development database when you run 'rake'.
# # Do not set this db to the same as development or production.
# test:
#   adapter: sqlite3
#   encoding: utf8
#   database: subscriptions_test
#   username: root
#   password:
# 
# production:
#   adapter: sqlite3
#   encoding: utf8
#   database: subscriptions_production
#   username: root
#   password: 

development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

这是模式

# encoding: UTF-8
# This file is auto-generated from the current state of the database. Instead
# of editing this file, please use the migrations feature of Active Record to
# incrementally modify your database, and then regenerate this schema definition.
#
# Note that this schema.rb definition is the authoritative source for your
# database schema. If you need to create the application database on another
# system, you should be using db:schema:load, not running all the migrations
# from scratch. The latter is a flawed and unsustainable approach (the more migrations
# you'll amass, the slower it'll run and the greater likelihood for issues).
#
# It's strongly recommended to check this file into your version control system.

ActiveRecord::Schema.define(:version => 20121218041922) do

  create_table "accounts", :force => true do |t|
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "full_domain"
    t.datetime "deleted_at"
  end

  add_index "accounts", ["full_domain"], :name => "index_accounts_on_full_domain"

  create_table "categories", :force => true do |t|
    t.datetime "created_at",  :null => false
    t.datetime "updated_at",  :null => false
    t.string   "name"
    t.string   "tutorial_id"
  end

  create_table "categories_tutorials", :force => true do |t|
    t.integer "category_id"
    t.integer "tutorial_id"
  end

  create_table "clients", :force => true do |t|
    t.datetime "created_at",         :null => false
    t.datetime "updated_at",         :null => false
    t.string   "address"
    t.string   "city"
    t.string   "company"
    t.string   "email"
    t.string   "name"
    t.string   "phone"
    t.string   "state"
    t.string   "website"
    t.string   "zip"
    t.string   "photo"
    t.string   "photo_file_name"
    t.string   "photo_content_type"
    t.integer  "photo_file_size"
    t.datetime "photo_updated_at"
  end

  create_table "clients_projects", :force => true do |t|
    t.integer "project_id"
    t.integer "client_id"
  end

  create_table "contracts", :force => true do |t|
    t.string   "title"
    t.integer  "client_id"
    t.string   "body"
    t.integer  "status"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "custom_documents", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
    t.string   "title"
    t.string   "body"
    t.integer  "client_id"
    t.boolean  "status"
  end

  create_table "documents", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "invoices", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "project_comments", :force => true do |t|
    t.integer  "user_id"
    t.integer  "project_id"
    t.string   "comment"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
    t.string   "user_name"
  end

  create_table "project_files", :force => true do |t|
    t.datetime "created_at",        :null => false
    t.datetime "updated_at",        :null => false
    t.string   "title"
    t.integer  "project_id"
    t.string   "file_file_name"
    t.string   "file_content_type"
    t.integer  "file_file_size"
    t.datetime "file_updated_at"
  end

  create_table "project_todo_comments", :force => true do |t|
    t.string   "comment"
    t.integer  "user_id"
    t.integer  "project_todo_id"
    t.integer  "project_todo"
    t.datetime "created_at",      :null => false
    t.datetime "updated_at",      :null => false
    t.integer  "project_id"
  end

  create_table "project_todos", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
    t.string   "due_date"
    t.string   "title"
    t.boolean  "status"
    t.integer  "project_id"
    t.datetime "due"
  end

  create_table "projectcommentations", :force => true do |t|
    t.integer  "project_id"
    t.integer  "user_id"
    t.string   "user_name"
    t.integer  "comment_id"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  create_table "projectmemberizations", :force => true do |t|
    t.integer  "project_id"
    t.integer  "user_id"
    t.date     "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

# Could not dump table "projects" because of following StandardError
#   Unknown type 'project' for column 'project_todo_due'

  create_table "projects_clients", :force => true do |t|
    t.integer "project_id"
    t.integer "client_id"
  end

  create_table "projects_users", :force => true do |t|
    t.integer "user_id"
    t.integer "project_id"
  end

  create_table "projecttodocomments_projecttodos", :force => true do |t|
    t.integer "project_todo_comment_id"
    t.integer "project_todo_id"
  end

  create_table "proposals", :force => true do |t|
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
    t.string   "body"
    t.integer  "client_id"
    t.boolean  "status"
    t.string   "title"
  end

  create_table "saas_admins", :force => true do |t|
    t.string   "email",                                 :default => "", :null => false
    t.string   "encrypted_password",     :limit => 128, :default => "", :null => false
    t.string   "password_salt",                         :default => "", :null => false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",                         :default => 0
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string   "current_sign_in_ip"
    t.string   "last_sign_in_ip"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  add_index "saas_admins", ["email"], :name => "index_admins_on_email", :unique => true
  add_index "saas_admins", ["reset_password_token"], :name => "index_admins_on_reset_password_token", :unique => true

  create_table "subscription_affiliates", :force => true do |t|
    t.string   "name"
    t.decimal  "rate",       :precision => 6, :scale => 4, :default => 0.0
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "token"
  end

  add_index "subscription_affiliates", ["token"], :name => "index_subscription_affiliates_on_token"

  create_table "subscription_discounts", :force => true do |t|
    t.string   "name"
    t.string   "code"
    t.decimal  "amount",                 :precision => 6, :scale => 2, :default => 0.0
    t.boolean  "percent"
    t.date     "start_on"
    t.date     "end_on"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.boolean  "apply_to_setup",                                       :default => true
    t.boolean  "apply_to_recurring",                                   :default => true
    t.integer  "trial_period_extension",                               :default => 0
  end

  create_table "subscription_payments", :force => true do |t|
    t.integer  "subscriber_id"
    t.integer  "subscription_id"
    t.decimal  "amount",                    :precision => 10, :scale => 2, :default => 0.0
    t.string   "transaction_id"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.boolean  "setup"
    t.boolean  "misc"
    t.integer  "subscription_affiliate_id"
    t.decimal  "affiliate_amount",          :precision => 6,  :scale => 2, :default => 0.0
    t.string   "subscriber_type",                                          :default => "User"
  end

  add_index "subscription_payments", ["subscriber_id", "subscriber_type"], :name => "index_subscription_payments_on_subscriber"
  add_index "subscription_payments", ["subscription_id"], :name => "index_subscription_payments_on_subscription_id"

  create_table "subscription_plans", :force => true do |t|
    t.string   "name"
    t.decimal  "amount",         :precision => 10, :scale => 2
    t.datetime "created_at"
    t.datetime "updated_at"
    t.integer  "renewal_period",                                :default => 1
    t.decimal  "setup_amount",   :precision => 10, :scale => 2
    t.integer  "trial_period",                                  :default => 1
    t.integer  "user_limit"
    t.float    "unit_price"
    t.text     "description"
    t.boolean  "featured",                                      :default => false
    t.string   "trial_interval",                                :default => "months"
  end

  create_table "subscriptions", :force => true do |t|
    t.decimal  "amount",                    :precision => 10, :scale => 2
    t.datetime "next_renewal_at"
    t.string   "card_number"
    t.string   "card_expiration"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "state",                                                    :default => "trial"
    t.integer  "subscription_plan_id"
    t.integer  "subscriber_id"
    t.integer  "renewal_period",                                           :default => 1
    t.string   "billing_id"
    t.integer  "user_limit"
    t.integer  "subscription_discount_id"
    t.integer  "subscription_affiliate_id"
    t.string   "subscriber_type",                                          :default => "User"
  end

  add_index "subscriptions", ["subscriber_id", "subscriber_type"], :name => "index_subscriptions_on_subscriber_id_and_subscriber_type"

  create_table "tutorials", :force => true do |t|
    t.datetime "created_at",   :null => false
    t.datetime "updated_at",   :null => false
    t.string   "content"
    t.string   "title"
    t.integer  "user_id"
    t.integer  "category_ids"
  end

  create_table "users", :force => true do |t|
    t.string   "name"
    t.string   "email",                                   :null => false
    t.string   "encrypted_password",                      :null => false
    t.string   "password_salt",                           :null => false
    t.datetime "last_sign_in_at"
    t.datetime "current_sign_in_at"
    t.string   "last_sign_in_ip"
    t.string   "current_sign_in_ip"
    t.integer  "account_id"
    t.boolean  "admin",                :default => false
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "confirmation_token"
    t.datetime "confirmed_at"
    t.datetime "confirmation_sent_at"
    t.string   "reset_password_token"
    t.string   "remember_token"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",        :default => 0
    t.integer  "failed_attempts",      :default => 0
    t.string   "unlock_token"
    t.datetime "locked_at"
    t.string   "photo_file_name"
    t.string   "photo_content_type"
    t.integer  "photo_file_size"
    t.datetime "photo_updated_at"
    t.string   "rate"
    t.string   "description"
    t.string   "web"
    t.string   "twitter"
    t.string   "dribbble"
    t.string   "github"
  end

  add_index "users", ["account_id"], :name => "index_users_on_account_id"
  add_index "users", ["confirmation_token"], :name => "index_users_on_confirmation_token", :unique => true
  add_index "users", ["email"], :name => "index_users_on_email"
  add_index "users", ["reset_password_token"], :name => "index_users_on_reset_password_token", :unique => true
  add_index "users", ["unlock_token"], :name => "index_users_on_unlock_token", :unique => true

  create_table "users_projects", :force => true do |t|
    t.integer "user_id"
    t.integer "project_id"
  end

end

---

加载rake db:schema:load更正了问题。

加载rake db:schema:load更正了问题。

实际问题是没有这样的表“project\u todos”，因此alter table命令无法执行。

步骤1：打开终端执行以下命令

$rails控制台

加载开发环境（Rails 4.1.0）

2.1.1:001>ActiveRecord:：Migration.创建表格（：项目TODO）此步骤将创建表格

2.1.1:002>退出

步骤2：然后通过执行

---

rake db:migrate实际问题是没有这样的表“project\u todos”，因此alter table命令无法执行。

步骤1：打开终端执行以下命令

$rails控制台

加载开发环境（Rails 4.1.0）

2.1.1:001>ActiveRecord:：Migration.创建表格（：项目TODO）此步骤将创建表格

2.1.1:002>退出

步骤2：然后通过执行

---

rake db:migrate

它的意思是说没有project\u todos表，应该有，还是名称不对？你是不是一开始用rake db:create创建数据库的？是的，应该有。我还没有写一行代码，我在控制器中看到对它的调用/views@regmiprem我在运行迁移之后做了rake db:drop，然后又做了rake db:create，同样的问题。你可以尝试加载模式，而不是运行迁移：

rake db:schema:load

，或者名称是错误的？您是否首先通过rake db:create创建了数据库？是的，应该有。我还没有写一行代码，我在控制器中看到对它的调用/views@regmiprem我在运行迁移和相同的问题之后，先执行了rake db:drop，然后执行了rake db:create。您可以尝试加载架构，而不是运行迁移：

rake db:schema:load