我的mail_type屬性正在更新..但我不明白爲什麼？

Question

def update 
    debugger 
    @email_blast = EmailBlast.find(params[:id]) 
    if @email_blast.update_attributes(params[:email_blast]) 
     debugger 
     # changes mail_type here 
     flash[:notice] = 'Email Blast Saved.' 
     if params[:id] == "1" 
     Delayed::Job.enqueue MassEmail.new(params[:email_blast][:subject], params[:email_blast][:body]) 
     elsif params[:id] == "2" 
     Delayed::Job.enqueue OrgBlast.new(params[:email_blast][:subject], params[:email_blast][:body]) 
     elsif params[:id] == "3" 
     Delayed::Job.enqueue MagicEmail.new(params[:email_blast][:subject], params[:email_blast][:body]) 
     elsif params[:id] == "4" 
     Delayed::Job.enqueue OrgMagicEmail.new(params[:email_blast][:subject], params[:email_blast][:body]) 
     end 
     redirect_to edit_admin_email_blast_path(params[:id]) 
    end 
end 

這有多奇怪？一旦通過此控制器代碼，@ email_blast.mail_type被更改爲「card_holder」。爲什麼會發生？第一調試回報PARAMS：

(rdb:407) @email_blast = EmailBlast.find(params[:id]) 
#<EmailBlast id: 3, subject: "HQMagic Email", body: "asdfasdfasdfasdfas<br />\r\nd<br />\r\nfas<br />\r\ndf<br...", mail_type: "magic_email", created_at: "2010-10-28 14:57:48", updated_at: "2010-11-04 20:51:45"> 

而第二個：

{"body"=>"asdfasdfasdfasdfas<br />\r\nd<br />\r\nfas<br />\r\ndf<br />\r\nasdf<br />\r\nas<br />\r\ndf<br />\r\nasd<br />\r\nfasd<br />\r\nfa<br />\r\nsd<br />\r\nfasd", "mail_type"=>"card_holders", "id"=>"3", "subject"=>"HQMagic Email"} 

Answer 1

如果你調用update_attributes和params[:email_blast][:mail_type]定義，那麼它將被重新分配。您始終可以將此參數設置爲受保護的以避免這種情況。