没有 Rails 的 Ruby/Postgres ActiveRecord : Undefined Table ERROR: relation "..." does not exist

Question

使用小型 Rub​​y 脚本来创建数据并将数据存储到 Postgres 数据库。在创建和删除数据库或运行迁移时，该应用程序运行良好。但是，当我尝试运行 rake db:seed 时它失败了。错误消息表明该表不存在...但与此同时，如果我运行错误消息中引用的相同 SQL 脚本，但在 pgAdmin 中，它会返回有效结果。我想知道授予 database.yml 中命名的用户的权限是否有问题，如果有，我将如何在脚本中解决这个问题？任何有助于理解这一点的帮助将不胜感激。

这是我在终端中收到的错误消息:

acmecorp$ rake db:seed
rake aborted!
ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  relation "applications" does not exist
LINE 8:                WHERE a.attrelid = '"applications"'::regclass
                                          ^
:               SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
                     c.collname, col_description(a.attrelid, a.attnum) AS comment
                FROM pg_attribute a
                LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                LEFT JOIN pg_type t ON a.atttypid = t.oid
                LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation
               WHERE a.attrelid = '"applications"'::regclass
                 AND a.attnum > 0 AND NOT a.attisdropped
               ORDER BY a.attnum
/Users/thisguy/repositories/acmecorp/db/seeds.rb:1:in `<top (required)>'
/Users/thisguy/repositories/acmecorp/rakefile.rb:30:in `require_relative'
/Users/thisguy/repositories/acmecorp/rakefile.rb:30:in `block (2 levels) in <top (required)>'

Caused by:
PG::UndefinedTable: ERROR:  relation "applications" does not exist
LINE 8:                WHERE a.attrelid = '"applications"'::regclass
                                          ^
/Users/thisguy/repositories/acmecorp/db/seeds.rb:1:in `<top (required)>'
/Users/thisguy/repositories/acmecorp/rakefile.rb:30:in `require_relative'
/Users/thisguy/repositories/acmecorp/rakefile.rb:30:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)

我的database.yml文件:

# config/database.yml
default: &default
  host: 'localhost'
  adapter: 'postgresql'
  encoding: utf-8

development:
  <<: *default
  database: 'acmecorp_dev'
  username: 'acmecorpapp'

Gemfile 非常简单:

# Gemfile
source 'https://rubygems.org'

gem 'activerecord'
gem 'require_all'
gem 'pg'

我有一个 rakefile.rb 来控制各种任务(编辑以删除不相关的项目):

# rakefile.rb
require "active_record"
require "require_all"
require "yaml"

namespace :db do
  env = 'development' || ENV['env']

  db_config       = YAML::load(File.open('config/database.yml'))[env]
  db_config_admin = db_config.merge({'database' => 'postgres', 'schema_search_path' => 'public'})

  ...

  desc "Seed the database"
  task :seed do
    ActiveRecord::Base.establish_connection(db_config_admin)
    require_all 'models/*.rb'
    require_relative 'db/seeds.rb'
  end

  ...

end

如前所述，rakefile 中的所有其他任务都可以正常工作——只有 :seed 任务会打嗝。我相当有信心它与脚本与数据库交互的方式有关。

这是种子文件:

# db/seeds.rb
Application.create({
  ApplicationNumber:  1,
  AccountNumber: 1234,
  ApplVer:  1,
  CreateDateTime:  "1/2/2018",
  ExpirationDateTime:  "1/5/2019",
  ApplicationStatus:  "In process",
  ApprovedAmount:     1992.92,
  AcceptedAmount:     92.92,
  HomeAddressLine1:   "1 Main Street",
  HomeAddressLine2:   "",
  HomeAddressCity:    "Thibodaux",
  HomeAddressState:   "LA",
  HomeAddressZipCode: "12345"
})

最后，我有一个应用程序的简单模型，seeds.rb 文件引用了它:

# models/application.rb
class Application < ActiveRecord::Base
end

现在上面提到的错误消息表明“关系“应用程序”不存在”......但是当我运行消息中引用的相同 SQL 时，直接在 pgAdmin 中，这就是我得到的(格式化的道歉 - 不能'弄清楚如何有效地将它放入表格中):

attname|format_type|pg_get_expr|attnotnull|atttypid|atttypmod|collname|comment
id|integer|nextval('applications_id_seq'::regclass)|t|23|-1||
ApplicationNumber|integer||f|23|-1||
AccountNumber|integer||f|23|-1||
ApplVer|integer||f|23|-1||
CreateDateTime|timestamp without time zone||f|1114|-1||
ExpirationDateTime|timestamp without time zone||f|1114|-1||
ApplicationStatus|character varying||f|1043|-1||
ApprovedAmount|numeric||f|1700|-1||
AcceptedAmount|numeric||f|1700|-1||
HomeAddressLine1|character varying||f|1043|-1||
HomeAddressLine2|character varying||f|1043|-1||
HomeAddressCity|character varying||f|1043|-1||
HomeAddressState|character varying||f|1043|-1||
HomeAddressZipCode|character varying||f|1043|-1||
FileCreatedDate|timestamp without time zone||f|1114|-1||
created_at|timestamp without time zone||t|1114|-1||
updated_at|timestamp without time zone||t|1114|-1||

所以底线似乎是: - 脚本已正确配置以与 PG 一起使用 - 至少在创建、删除和迁移数据库方面 - rake db:seed 任务失败 - 命令行错误消息中报告的 SQL 在通过 pgAdmin 运行时工作正常

我不确定为什么会这样。它可能与分配给 database.yml.. 中的数据库的 acmecorpapp 用户可用的权限有关吗？

Answer 1

请检查文件 rakefile.rb。看来你合并了错误的数据库。用于开发的数据库是 acmecorp_dev，您已经在 db_config 中拥有它。我认为您不必再​​合并 database 了。试试这个:

require "active_record"
require "require_all"
require "yaml"

namespace :db do
  env = 'development' || ENV['env']

  db_config       = YAML::load(File.open('config/database.yml'))[env]
  db_config_admin = db_config.merge({ 'schema_search_path' => 'public'})

  ...

  desc "Seed the database"
    task :seed do
    ActiveRecord::Base.establish_connection(db_config_admin)
    require_all 'models/*.rb'
    require_relative 'db/seeds.rb'
 end

 ...

end