Sinatra 中的 DataMapper 错误 - NameError: 找不到 child_model

Question

使用 Sinatra 和 DataMapper。这是我第一次尝试使用两个以上的模型类。不确定是什么导致了错误。谢谢。

错误：

NameError: Cannot find the child_model ContactNote for Contact in contact_notes

模型：

class Contact
    include DataMapper::Resource
    property :id, Serial
    property :fullname, Text, :required => true
    property :email, Text
    property :phone, Text
    has n, :contact_notes
    has n, :projects
end

class Contact_Note
    include DataMapper::Resource
    property :id, Serial
    property :contact_content, Text, :required => true
    property :created_at, DateTime
    property :updated_at, DateTime
    belongs_to :contact
end

class Project
    include DataMapper::Resource
    property :id, Serial
    property :project_name, Text, :required => true
    property :created_at, DateTime
    property :updated_at, DateTime
    belongs_to :contact
    has n, :project_notes
end


class Project_Note
    include DataMapper::Resource
    property :id, Serial
    property :project_content, Text, :required => true
    property :created_at, DateTime
    property :updated_at, DateTime
    belongs_to :project
end

Answer 1

Datamapper 根据 ruby​​ 约定对类名做出预期。它希望您的联系笔记属于ContactNote 类，而您已将其命名为Contact_Note，因此它找不到ContactNote 的错误。