Rails拥有城市的独特国家 [英] Rails get unique country with cities

问题描述

如何列出唯一的国家和相关城市？以下是我的产品表：

How can I list unique country followed by related cities? Following were my product table:

name  country   city
p1     US        New York
p2     US        Boston
p3     US        Chicago
k1     UK        London
k2     UK        Liverpool

控制器：

@countries = Product.joins(:user).distinct.where("country is not null and country <> ''").where(:users => {:merchant_status => 1}).pluck(:country)

@cities = Product.joins(:user).distinct.where("city is not null and city <> ''").where(:users => {:merchant_status => 1}).pluck(:city)

@countries.map! {|country| country.split.map(&:capitalize).join(' ')}

@search_location_country = @countries

在我看来：

<ul id="color-dropdown-menu" class="dropdown-menu dropdown-menu-right" role="menu">

  <% @search_location_country.each do |country| %>
    <li class="input"><a href="#"><%= country %></a></li>
  <% end %>
</ul>

如何对最终结果进行排序，如下所示：

How can I sort the end result for drop down like this:

US
 - New York
 - Boston
 - Chicago
UK
 - London
 - Liverpool

谢谢！

编辑

要显示如下内容：

推荐答案

嘿，您可以使用 group 尝试这种方式不同的记录

Hey you can try this way using group it gives you all distinct records

@countries_cities = Product.joins(:user).where("country is not null and country <> ''").where("city is not null and city <> ''").where(:users => {:merchant_status => 1}).group(:country, :city).select("country,city").as_json

它将为您提供输出，例如

It will give you output like

[{:country => "US", :city => "New York"}..]

如果要再次按国家/地区分组，请使用

If you want to again group it by country then used like

cchs = @countries_cities.group_by{|cc| cc["country"]}

将上述多维数组转换为使用

Convert above multidimensional array to hash using

@country_cities_hash =  = Hash[*cchs]

在您的视图文件中为

<% @country_cities_hash.each do |country, cities| %>
  <li class="input"><a href="#"><%= country %></a></li>
 <%  cities.each do |city| %>
  <li class="input"><a href="#"><%= "#{city}(#{country})" %></a></li>
  <% end %>
<% end %>

这篇关于Rails拥有城市的独特国家的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！