Question

在Rails项目中，如果它属于Single User，我正在尝试生成Category的名称数组。

例如，用户A有两个类别，如LandLord和PropertyBroker。

用户模型

class User < ActiveRecord::Base

  has_many :users_categories
  has_many :categories, through: :users_categories

  scope :users_categories_active, -> { joins(:users_categories)
                                       .where('users_categories.status = ?', true) }
  def self.with_selected_active_user
    select("users.id, users.first_name, users.city, categories.name,
                                           users_categories.status, users_categories.id")
  end
end

类别模型

class Category < ActiveRecord::Base
  has_many :users_categories
  has_many :users, through: :users_categories
end

UserCategory模型

class UserCategory < ActiveRecord::Base
  belongs_to :user
  belongs_to :category
end

查询

user_list = User.joins(:categories, :users_categories)
                         .with_selected_active_user.users_categories_active.uniq
render :json => user_list

输出

[{"id":2,"first_name":"Adam","city":"Mumbai","status":true,"name":"LandLord"},
 {"id":3,"first_name":"Charles","city":"Delhi","status":true,"name":"Tenant"},
 {"id":1,"first_name":"Adam","city":"Mumbai","status":true,"name":"ProperyBroker"}
]

我试图以不同的模式生成此输出

 [{"first_name":"Adam","city":"Mumbai","status":true,"name":"['LandLord','ProperyBroker'"},
 {"first_name":"Charles","city":"Delhi","status":true,"name":"Tenant"} 
 ]

总而言之，我想将类别名称放在一个数组中。

Answer 1

在您的查询中使用group，如下所示 -

user_list = User.joins(:categories, :users_categories)
              .with_selected_active_user.users_categories_active.group(" first_name, city, status, name ")
render :json => user_list

Answer 2

{{1}}

=＆GT; [{：status =＆gt; true，：names =＆gt; [“LandLord”，“ProperyBroker”]，：city =＆gt;“Mumbai”}， {：status =＆gt; true，：names =＆gt; [“Tenant”]，：city =＆gt;“Delhi”}]

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2 个答案: