關於ROR ONE_TO_ONE時，嵌套表單顯示不出來的問題

In your code: <% f.fields_for :profile do |profile_form| %> Doesn't that need to be written like this (due to Rails 3 new behavior): <%= f.fields_for :profile do |profile_form| %>

當one to one 類型的表關係，想經過nested關係嵌套form實現，在form這個級別裏，記得fields_for前面要加=纔好用。

而若是是下一級，也就是form裏面的one to many的fields_for裏面再嵌套一級one to none，則不須要等號=。