CSV到DataMapper導入

Question

這可能很簡單，但我對Ruby和活動記錄頗爲陌生。

我有一個數據庫的CSV轉儲，我試圖使用DataMapper導入到數據庫。我無法理解我應該在模型中定義哪種類型的關係，以便它與所定義的CSV匹配。

下面是我從CSV得到了什麼數據：

Stages: 
id 
staff_id 
project_id 
job_id 
company_id 

Projects: 
id 
company_id 

Jobs: 
id 
project_id 
company_id 

Client: 
id 

Staff: 
id 

例如：做階段belong_to項目或者是這個的has_many關係？

Answer 1

我假設客戶==公司。這裏的ActiveRecord

class Stage < ActiveRecord::Base 
    belongs_to :staff 
    belongs_to :project 
    belongs_to :job 
    belongs_to :company, :class => "Client" 
end 

class Project < ActiveRecord::Base 
    belongs_to :company, :class => "Client" 
    has_many :stages 
end 

class Job < ActiveRecord::Base 
    belongs_to :project 
    belongs_to :company, :class => "Client" 
    has_many :stages 
end 

class Client < ActiveRecord::Base 
    has_many :jobs, :foreign_key => "company_id" 
    has_many :projects, :foreign_key => "company_id" 
    has_many :stages, :foreign_key => "company_id" 
end 

class Staff < ActiveRecord::Base 
    has_many :stages 
end 

這裏DataMapper的一個例子爲例：

class Stage 
    include DataMapper::Resource 
    property :id, Serial 
    belongs_to :staff 
    belongs_to :project 
    belongs_to :job 
    belongs_to :company, "Client" 
end 

class Project 
    include DataMapper::Resource 
    property :id, Serial 
    belongs_to :company, "Client" 
    has n, :stages 
end 

class Job 
    include DataMapper::Resource 
    property :id, Serial 
    belongs_to :project 
    belongs_to :company, "Client" 
    has n, :stages 
end 

class Client 
    include DataMapper::Resource 
    property :id, Serial 
    has n, :jobs, :foreign_key => "company_id" 
    has n, :projects, :foreign_key => "company_id" 
    has n, :stages, :foreign_key => "company_id" 
end 

class Staff 
    include DataMapper::Resource 
    property :id, Serial 
    has n, :stages 
end 

對於你應該做一個特殊的順序導入：

1. Client，Staff，因爲他們可以存在獨立於所有其他型號
2. Project，它僅取決於Client
3. Job，取決於Project和Client
4. Stage，您使用的ActiveRecord或者DataMapper的取決於Staff，Project，Job和Client