PG::UndefinedColumn: ERROR: column sections.row_order does not exist

Question

<% @course.sections.rank(:row_order).each do |section| %>
    <br /><br />
        <div class="section">
            <h3>
                <%= section.title %>
            </h3>

我在部分中得到该行顺序的未定义列。这是我的部分模型...

class Section < ActiveRecord::Base
belongs_to :course
has_many :lessons

include RankedModel
ranks :row_order, :with_same => :course_id
end

这是我的迁移。

class AlterSectionsAddRowOrder < ActiveRecord::Migration
  def change
    add_column :sections, :row_order, :integer
    add_index :sections, :row_order
  end
end

如果这有用，这是我收到的错误消息。

在 2015 年 5 月 7 日开始为 10.0.2.2 获取“/courses/13”23:41:49 +0000 CoursesController 处理#show as HTML 参数：{"id"=>"13"} 课程负荷 (0.5ms) SELECT "courses".* FROM "courses" WHERE "courses"."id" = $1 LIMIT 1 [["id", "13 “]] 用户负载 (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = 2 ORDER BY "users"."id" 上升限制 1 用户负载 (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" 上升限制 1 [["id", 2]] Course Exists (0.4ms) SELECT 1 AS one FROM "courses" INNER JOIN "enrollments" ON "courses"."id" = "enrollments"."course_id" 其中 "enrollments"."user_id" = $1 AND "courses"."id" = 13 限制 1 [["user_id", 2]] 部分负载 (1.0ms) SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC [["course_id", 13]] PG::UndefinedColumn：错误：列 sections.row_order 不存在第 1 行：...ons" WHERE "sections"."course_id" = $1 ORDER BY "sections"... ^ : SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC 在 layouts/application（57.0 毫秒）内呈现 courses/show.html.erb 在 240 毫秒内完成 500 个内部服务器错误

ActionView::Template::Error（PG::UndefinedColumn：错误：列 sections.row_order 不存在第 1 行：...ons" WHERE "sections"."course_id" = $1 ORDER BY "sections"... ^ : SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC): 42： 43： 44： 45: <% @course.sections.rank(:row_order).每个做 |section| %> 46:

47： 48: 应用/视图/courses/show.html.erb:45:在`_app_views_courses_show_html_erb___522001594__582727588'

渲染 /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/_trace.erb (2.0ms) 渲染 /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.9ms) /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/template_error.erb rescues/layout (19.6ms)

在 2015 年 5 月 7 日开始为 10.0.2.2 获取“/courses/13”23:41:51 +0000 CoursesController 处理#show as HTML 参数：{"id"=>"13"} 课程负荷 (0.5ms) SELECT "courses".* FROM "courses" WHERE "courses"."id" = $1 LIMIT 1 [["id", "13 “]] 用户负载 (0.6ms) SELECT "users".* FROM "users" WHERE "users"."id" = 2 ORDER BY "users"."id" 上升限制 1 用户负载 (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" 上升限制 1 [["id", 2]] 课程存在（0.3 毫秒）SELECT 1 作为一个来自 "courses" INNER JOIN "enrollments" ON "courses"."id" = "enrollments"."course_id" 其中 "enrollments"."user_id" = $1 AND "courses"."id" = 13 限制 1 [["user_id", 2]] 部分负载 (0.7ms) SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC [["course_id", 13]] PG::UndefinedColumn：错误：列 sections.row_order 不存在第 1 行：...ons" WHERE "sections"."course_id" = $1 ORDER BY "sections"... ^ : SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC 在 layouts/application（51.8 毫秒）内呈现 courses/show.html.erb 在 163 毫秒内完成 500 个内部服务器错误

ActionView::Template::Error（PG::UndefinedColumn：错误：列 sections.row_order 不存在第 1 行：...ons" WHERE "sections"."course_id" = $1 ORDER BY "sections"... ^ : SELECT "sections".* FROM "sections" WHERE "sections"."course_id" = $1 ORDER BY "sections"."row_order" ASC): 42： 43： 44： 45: <% @course.sections.rank(:row_order).每个做 |section| %> 46:

47： 48: 应用/视图/courses/show.html.erb:45:在`_app_views_courses_show_html_erb___522001594__582727588'

渲染 /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/_trace.erb (3.6ms) 渲染 /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (2.3ms) /home/vagrant/.rbenv/versions/2.0.0-p353/lib/ruby/gems/2.0.0/gems/actionpack-4.0.1/lib/action_dispatch/middleware/templates/rescues/template_error.erb rescues/layout (21.3ms)

Answer 1

我的直接猜测是您忘记了运行迁移，并且从未添加该列。您可以通过查看 db/schema.rb 文件确认该列存在（并且迁移是运行）。

Answer 2

我尝试重新启动服务器，添加新的迁移，并检查每个代码。受挫后，我就是这样做的..

耙子db:drop 耙子 db:create 耙子 db:migrate

所有数据都消失了。但是网站现在运行又正常了。

PG::UndefinedColumn: ERROR: column sections.row_order does not exist

PG::UndefinedColumn: ERROR: column sections.row_order does not exist

mysql

migration

ruby-on-rails

ruby-on-rails-3