Question

我陷入了奇怪的情景，我正在努力将现有的Rails 3应用升级到Rails 5应用。

使用rails 3，我有一个对象报告，其中包含许多组织

@report.organizations
#<ActiveRecord::Relation [#<Organization id: 1, name: "Org 1", description: nil, created_at: "2012-01-27", updated_at: "2019-01-15">]>
@report.organizations.count    # 1

当我将新的org对象放入现有的activerecord关系中时，它为我提供了包括新的org在内的新的activerecord关系。

@report.organizations<< Organization.new
[#<Organization id: 1, name: "Org 1", description: nil, created_at: "2012-01-27", updated_at: "2019-01-15">, #<Organization id: nil, name: nil, description: nil, created_at: nil, updated_at: nil>]
# Getting count
@report.organizations.count    # 2

使用rails 5，我遇到异常了

@report.organizations << Organization.new
*** NoMethodError Exception: undefined method `<<' for #<Organization::ActiveRecord_Relation:0x00007f93483e2640>

当我喜欢的时候

@report.organizations.to_a << Organization.new

它给了我

[#<Organization id: 1, name: "Org 1", description: nil, created_at: "2012-01-27", updated_at: "2019-01-15">, #<Organization id: nil, name: nil, description: nil, created_at: nil, updated_at: nil>]

但计数是Stil 1而不是2

@report.organizations.count    # 1

希望我的问题对您很清楚，请帮助我解决此问题。谢谢

Answer 1

根据the guide，它应该可以工作。如果不是，请尝试使用create：

 @report.organizations.create

Answer 2

当您使用新的定义时，您需要保存该变量例如

organization=Organization.new
organization.name = "organization 1"
organization.description= "Something description"
organization.save #save the array obj
Organization.count #1

其他使用create方法创建记录突然两者都相同

Organization.create(name:"org2",description: "something")
Organization.count #2

Answer 3

这对我有用：

a=[]
a << @report.organizations
a.count # => 1
a << Organization.new
a.count # => 2

Answer 4

这个怎么样：

@report_data = @report.organizations
@report_data.count # => 1
@report_data += [Organization.new]
@report_data.count # => 2

如何在Rails 5中将对象推入ActiveRecord :: Relation

4 个答案: