Ruby on rails ActiveRecord:：语句无效：PG:：UndefinedTable:错误：关系“类别”不存在

我正在构建一个小的rails应用程序。当我运行heroku run rake db:migrate时，我得到这个错误

rake aborted!

StandardError: An error has occurred, this and all later migrations canceled:

PG::UndefinedTable: ERROR:  relation "categories" does not exist
: CREATE TABLE "habits" ("id" serial primary key, "name" character varying, "description" character varying, "category_id" integer, "user_id" integer, "created_at
" timestamp NOT NULL, "updated_at" timestamp NOT NULL, CONSTRAINT "fk_rails_23642321ab"
FOREIGN KEY ("category_id")
  REFERENCES "categories" ("id")
, CONSTRAINT "fk_rails_541267aaf9"
FOREIGN KEY ("user_id")
  REFERENCES "users" ("id")
)

为了解决这个问题，我还将其添加到definctions.rb中

ActiveSupport::Inflector.inflections do |inflect|
  inflect.irregular 'category', 'categories'

  inflect.plural 'category', 'categories'
end

这没用

我还查看了有关stackoverflow的一些答案，包括，但没有帮助，因为我在运行迁移命令时遇到了这个错误

这是我的分类和习惯迁移文件

class CreateCategories < ActiveRecord::Migration[5.0]
  def change
    create_table :categories do |t|
      t.string :name

      t.timestamps
    end
  end
end

class CreateHabits < ActiveRecord::Migration[5.0]
  def change
    create_table :habits do |t|
      t.string :name
      t.string :description

      t.integer :user_id
      t.integer :category_id

      t.timestamps
    end
  end
end

---

不知道我还错过了什么

似乎您的迁移文件就是问题所在。也许可以试试rakedb:schema:load。我以前也遇到过类似的问题，这总是因为在初始迁移之后添加了一个列

您的迁移似乎有问题。在本地运行此命令，查看它们是否运行正常：rake db:drop&&rake db:create&&rake db:migrate

---

PS：我没有告诉您运行rake db:reset，因为这样会加载模式而不是运行迁移。

最后，我不得不销毁我的Heroku应用程序并重新创建它。解决了这个问题。我的应用程序中没有太多数据。所以，我能做到。如果你有一个非常好的数据库，我不会建议你这么做

要销毁应用程序，heroku应用程序：销毁

---

要再次创建它，heroku create appname

检查添加/修改/删除引用的迁移。嗯，我们可以看看您的模式吗？也不确定，但这可能会有帮助，非常感谢您的时间。我已经编辑了我的问题以包括schema.rbAlright。我最好的猜测仍然是迁移的顺序。这个问题的答案可能是一个解决方案：另一方面，我不想这么说，但是heroku运行rake db:reset或rake db:drop:all，然后重新尝试迁移。如果您有不想销毁的数据，则这些选项不在表中。此外，根据您在模型中进行引用的方式，迁移可能必须是t.references设置。ctrl+f引用第二个：添加\引用：产品，：用户，外键：真的好运气，我希望有东西适合你！

# 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 that you check this file into your version control system.

ActiveRecord::Schema.define(version: 20170612231416) do

  create_table "categories", force: :cascade do |t|
    t.string   "name"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "comments", force: :cascade do |t|
    t.text     "description"
    t.integer  "habit_id"
    t.integer  "user_id"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
  end

  create_table "goals", force: :cascade do |t|
    t.string   "name"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "goals_habits", force: :cascade do |t|
    t.integer  "habit_id"
    t.integer  "goal_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "goals_milestones", force: :cascade do |t|
    t.integer  "goal_id"
    t.integer  "milestone_id"
    t.datetime "created_at",   null: false
    t.datetime "updated_at",   null: false
  end

  create_table "habits", force: :cascade do |t|
    t.string   "name"
    t.string   "description"
    t.integer  "user_id"
    t.integer  "category_id"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
  end

  create_table "milestones", force: :cascade do |t|
    t.string   "description"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
  end

  create_table "milestones_statuses", force: :cascade do |t|
    t.integer  "milestone_id"
    t.integer  "status_id"
    t.datetime "created_at",   null: false
    t.datetime "updated_at",   null: false
  end

  create_table "statuses", force: :cascade do |t|
    t.string   "description"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
  end

  create_table "users", force: :cascade do |t|
    t.string   "name"
    t.string   "email"
    t.string   "password_digest"
    t.datetime "created_at",      null: false
    t.datetime "updated_at",      null: false
    t.integer  "role"
  end

end