兩個belongs_to相同的模型使用名稱分配ID

Question

我是RoR的新手，並且正在創建數據庫。每個主機有兩個系統管理員。我試圖將創建主機時給出的名稱與其各自的系統管理員關聯。我會怎麼做呢？

如果用戶輸入系統管理員的名稱，那麼如何使用該名稱獲取該id並將該id插入到primary_sadmin_id字段中？

Systemadmin.rb

class Systemadmin < ActiveRecord::Base 
    attr_accessible :id, :email, :location, :name, :netid, :priphone, :secphone 
    has_many :primary_sysadmin, :class_name => 'Host', :foreign_key => 'primary_sadmin_id' 
    has_many :seconday_sysadmin, :class_name => 'Host', :foreign_key => 'seconary_sadmin_id' 
end 

host.rb

class Host < ActiveRecord::Base 
    attr_accessible :iogroup, :ip, :location, :name, :opsystem, :primary_sadmin_id, :purpose, :secondary_sadmin_id, :host_type 
    belongs_to :primary_sadmin, :class_name => 'Systemadmin', :foreign_key => 'primary_sadmin_id' 
    belongs_to :secondary_sadmin, :class_name => 'Systemadmin', :foreign_key => 'secondary_sadmin_id' 

end 

host_controller.rb

def create 
@host = Host.new(params[:host]) 
@host.primary_sadmin_id = Systemadmin.find_by_name(:sa_name1) 
@host.secondary_sadmin_id = Systemadmin.find_by_name(:sa_name2) 
respond_to do |format| 
    if @host.save 
    format.html { redirect_to @host, notice: 'Host was successfully created.' } 
    format.json { render json: @host, status: :created, location: @host } 
    else 
    format.html { render action: "new" } 
    format.json { render json: @host.errors, status: :unprocessable_entity } 
    end 
end 
end 

schema.rb

create_table "hosts", :force => true do |t| 
t.string "name" 
t.integer "ip",     :precision => 38, :scale => 0 
t.string "location" 
t.string "host_type" 
t.string "opsystem" 
t.string "iogroup" 
t.integer "primary_sadmin_id", :precision => 38, :scale => 0 
t.integer "secondary_sadmin_id", :precision => 38, :scale => 0 
t.string "purpose" 
t.datetime "created_at",           :null => false 
t.datetime "updated_at",           :null => false 
end 

create_table "systemadmins", :force => true do |t| 
t.string "name" 
t.string "netid" 
t.integer "priphone", :precision => 38, :scale => 0 
t.integer "secphone", :precision => 38, :scale => 0 
t.string "email" 
t.string "location" 
t.datetime "created_at",        :null => false 
t.datetime "updated_at",        :null => false 
end 

Answer 1

使用find_or_create_by_name解決它。

 
class Host 'Systemadmin', :foreign_key => 'primary_sadmin_id' 
    belongs_to :secondary_sadmin, :class_name => 'Systemadmin', :foreign_key => 'secondary_sadmin_id' 
    has_many :database, :class_name => 'Host' 


    def sa_name1 
    primary_sadmin.try(:sa_name1) 
    end 

    def sa_name1=(sa_name1) 
    self.primary_sadmin = Systemadmin.find_or_create_by_name(sa_name1) if sa_name1.present? 
    end 

    def sa_name2 
    secondary_sadmin.try(:sa_name2) 
    end 

    def sa_name2=(sa_name2) 
    self.secondary_sadmin = Systemadmin.find_or_create_by_name(sa_name2) if sa_name2.present? 
    end 

end