Rails命令column_names的集合

Question

我正在使用表单中的Rails表中的column_names。

column_names（）public 将列名称数组作为字符串返回。

如何订购收藏清单？

这不起作用：

<%= f.input :field_name, :label => "Field Name", :collection => Vehicle.column_names.order(:name) %>

我明白了：

undefined method `order' for #<Array

这不起作用：

<%= f.input :field_name, :label => "Field Name", :collection => Vehicle.column_names.sort_by{|e| e[:name]} %>

我明白了：

no implicit conversion of Symbol into Integer

Answer 1

Model.column_names 返回一个列名数组。

例如

Loading development environment (Rails 3.2.13)
#Customer is my rails model
2.1.2 :001 > Customer.column_names
 => ["id", "customer_name", "customer_tier", "customer_channel", "created_at", "updated_at"] 

#this sorts it
2.1.2 :002 > Customer.column_names.sort
 => ["created_at", "customer_channel", "customer_name", "customer_tier", "id", "updated_at"] 

Answer 2

<%= f.input :field_name, :label => "Field Name", :collection => Vehicle.column_names.sort{|a,b| a[:name] <=> b[:name]} %>

不确定您的数据收集情况如何，但我确信这应该有用。

干杯！