如何按列对集合进行分组

Question

我正在尝试按下面的属性集对我的产品属性进行分组，即我将尺寸设置为属性集，并希望将其分组为小、中、大等..

这是我目前拥有的代码，但我遇到了一些错误

- Property.all.group_by(&:property_set_id).each do |property_set, properties|
  h3= property_set.name
- properties.each do |property|
  = property.property_set.name
  .property_form.left.span-9.last
    - checked = property_set.name && property_set.properties.include?(property)
    label.mdl-switch.mdl-js-switch.mdl-js-ripple-effect for=property.name
      = check_box_tag "prototype[property_ids][]", property.id, checked, :class => 'mdl-switch__input', :id => property.name
      span.mdl-switch__label= property.name


  def edit
    @properties = Property.all
    @property_set = PropertySet.includes(:properties).find(params[:id])
  end

Answer 1

分组后的这一行 property_set 将是 id

- Property.all.group_by(&:property_set_id).each do |property_set, properties|

类似于：

{ 1 => [<#Property>], 2 => [<#Property>] }

因此您不能对整数值调用 .name。你需要从 db

中找到它

h3= PropertySet.find(property_set).try(:name)
# or
h3= properties.find{ |p| p.property_set_id == property_set}.property_set.try(:name) # to avoid query

如何按列对集合进行分组

How to group collection by columns

collections

grouping

ruby-on-rails

slim-lang