Rails 测试尝试删除 sql 视图

Posted 2023-02-26

【中文标题】Rails 测试尝试删除 sql 视图

【英文标题】：Rails tests trying to delete sql views

【发布时间】：2015-07-03 02:23:57

【问题描述】：

我正在尝试为我的应用程序编写单元和集成测试，但是当我运行 rake 测试时，我看到了很多错误，所有这些错误都是由系统试图删除只读的 sql 视图引起的。当测试只是为了验证数据创建时，为什么要尝试删除视图，以及如何让我的测试通过这个？该应用程序运行良好，但我无法让测试正常运行。 （在添加 sql 视图之前，所有测试都运行良好）。

这是我看到的错误：

    Finished in 0.779585s, 39.7647 runs/s, 0.0000 assertions/s.

  1) Error:
UsersControllerTest#test_should_get_new:
ActiveRecord::StatementInvalid: PG::ObjectNotInPrerequisiteState: ERROR:  cannot delete from view "playabilitysummary"
DETAIL:  Views that do not select from a single table or view are not automatically updatable.
HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
: DELETE FROM "playabilitysummary"


Error:
UsersControllerTest#test_should_get_new:
NoMethodError: undefined method `each' for nil:NilClass



  2) Error:
StaticPagesControllerTest#test_should_get_contactus:
ActiveRecord::StatementInvalid: PG::ObjectNotInPrerequisiteState: ERROR:  cannot delete from view "playabilitysummary"
DETAIL:  Views that do not select from a single table or view are not automatically updatable.
HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
: DELETE FROM "playabilitysummary"

可玩性总结模型：

class PlayabilitySummary < ActiveRecord::Base

self.table_name = 'playabilitysummary'
  after_initialize :readonly!

end

可玩性摘要迁移：

class CreatePlayabilitySummaries < ActiveRecord::Migration
  def up
    execute <<-SQL
   CREATE VIEW PlayabilitySummary AS
   SELECT date,user_id,speed,firmness,moisture FROM (((SELECT distinct(schedules.date) as date, speed.user_id as user_id, speed.speed as speed FROM schedules 
join
  (SELECT user_id, measure_date as speed_date, avg(speed) as speed FROM greens group by user_id, measure_date order by user_id, measure_date asc) as speed
on schedules.date = speed.speed_date) as avg1
JOIN
  (SELECT user_id as fuser_id, measure_date as firm_date, avg(firmness) as firmness FROM greens group by user_id, measure_date order by user_id, measure_date asc) as firmness
ON avg1.user_id = firmness.fuser_id AND avg1.date = firmness.firm_date) as avg2
JOIN
  (SELECT user_id as muser_id, measure_date as moist_date, avg(moisture) as moisture FROM greens group by user_id, measure_date order by user_id, measure_date asc) as moisture
ON avg2.fuser_id = moisture.muser_id AND avg2.date = moisture.moist_date)
      SQL
    end

def down
  execute 'DROP VIEW PlayabilitySummary'
end

end

示例测试（user_controller）：

require 'test_helper'

class UsersControllerTest < ActionController::TestCase
  test "should get new" do
    get :new
    assert_response :success
  end


end

【参考方案1】：

我在最近一次 rails/rspec 更新后遇到了这个问题，并认为以下内容可能有用。 如果您在迁移中执行任意 SQL 命令（例如创建视图或函数），这些可能会在运行测试时丢失，因为测试从 schema.rb 加载。

将format of the schema type 更改为 :sql 允许将整个结构转储到一个文件中，这意味着测试运行程序现在将选择这些：

# config/application.rb
config.active_record.schema_type = :sql

运行rake db:schema:dump 以生成必要的db/structure.sql 将停止在测试运行之间删除您的视图和函数。

【参考方案2】：

通过创建 rake db:views 任务来创建 sql 视图并从迁移中删除这些视图，此问题已得到解决。这使测试数据库准备不会尝试删除定义为只读的表。

此外，db 用户被授予超级用户访问权限。这两个步骤都成功消除了删除错误。

【讨论】：

谢谢，这里有一篇文章解释了如何做到这一点rietta.com/blog/2015/03/30/…，但我仍然遇到同样的错误