通过参数进行弹性搜索对象关联查询

Question

我在使用 Elastic Search 时遇到了一些困难，并且 Tyre 没有返回任何结果。我正在使用 Ruby 1.9.3 和 Rails 3.2.11。

在我的控制器中，我正在调用：

@location_id = 1
@listings = Listing.search(params.merge!(location_id: @location_id))

在我的列表模型中，我有

mapping do
    indexes :id, type: 'integer'
    ...
    indexes :author do
      indexes :location_id,     :type => 'integer', :index => :not_analyzed
      ...
end

def self.search(params={})
      tire.search(load: true, page: params[:page], per_page: 20) do |search|

      search.query  { string params[:query], :default_operator => "AND" } if params[:query].present?
      search.filter :range, posted_at: {lte: DateTime.now}

      search.filter :term, "author.location_id"       => params[:location_id]
end

我有 300 个结果，它们在数据库中的 location_id 都为 1，所以我似乎无法弄清楚为什么它返回一个 nil 集？如果我注释掉 author.location_id 搜索过滤器行，它会按预期返回所有其他结果？

Answer 1

在像您这样的情况下，有几件事需要解决。让我们从一个完整的工作代码开始：

require 'active_record'
require 'tire'
require 'logger'

# Tire.configure { logger STDERR }
# ActiveRecord::Base.logger = Logger.new(STDERR)

Tire.index('articles').delete

ActiveRecord::Base.establish_connection( adapter: 'sqlite3', database: ":memory:" )
ActiveRecord::Schema.define(version: 1) do
  create_table :articles do |t|
    t.string :title
    t.integer :author_id
    t.date    :posted_at
    t.timestamps
  end
  create_table :authors do |t|
    t.string  :name
    t.integer :number, :location_id
    t.timestamps
  end
  add_index(:articles, :author_id)
  add_index(:authors, :location_id)
end

class Article < ActiveRecord::Base
  belongs_to :author, touch: true
  self.include_root_in_json = false

  include Tire::Model::Search
  include Tire::Model::Callbacks

  mapping do
    indexes :title

    indexes :author do
      indexes :location_id, type: 'integer'
    end
  end

  def self.search(params={})
    tire.search load: {include: 'author'} do |search|
      search.query do |query|
        query.filtered do |f|
          f.query { params[:query].present? ? match([:title], params[:query], operator: 'and') : match_all }
          f.filter :range, 'posted_at' => { lte: DateTime.now }
          f.filter :term,  'author.location_id' => params[:location_id]
        end
      end
    end
  end

  def to_indexed_json
    to_json( only: ['title', 'posted_at'], include: { author: { only: [:location_id] } } )
  end
end

class Author < ActiveRecord::Base
  has_many :articles

  after_touch do
    articles.each { |a| a.tire.update_index }
  end
end

# -----

Author.create id: 1, name: 'John', location_id: 1
Author.create id: 2, name: 'Mary', location_id: 1
Author.create id: 3, name: 'Abby', location_id: 2

Article.create title: 'Test A', author: Author.find(1), posted_at: 2.days.ago
Article.create title: 'Test B', author: Author.find(2), posted_at: 1.day.ago
Article.create title: 'Test C', author: Author.find(3), posted_at: 1.day.ago
Article.create title: 'Test D', author: Author.find(3), posted_at: 1.day.from_now

Article.index.refresh

# -----

articles = Article.search query: 'test', location_id: 1
puts "", "Documents with location:1", '-'*80
articles.results.each { |a| puts "* TITLE: #{a.title}, LOCATION: #{a.author.location_id}, DATE: #{a.posted_at}" }

articles = Article.search query: 'test', location_id: 2
puts "", "Documents with location:2", '-'*80
articles.results.each { |a| puts "* TITLE: #{a.title}, LOCATION: #{a.author.location_id}, DATE: #{a.posted_at}" }
puts "(NOTE: 'D' is missing, because is not yet posted)"

articles = Article.search query: 'test b', location_id: 1
puts "", "Documents with query:B and location:1", '-'*80
articles.results.each { |a| puts "* TITLE: #{a.title}, LOCATION: #{a.author.location_id}, DATE: #{a.posted_at}" }

首先，像这样创建一个孤立的、提取的案例通常是个好主意。

在您的示例代码中，我假设您有一个关系Listing belongs_to :author。您需要正确定义映射和序列化，我再次假设您这样做了。

至于查询本身：

• 除非您使用分面导航，否则请使用 filtered 查询，而不是顶级过滤器，如我的示例代码中所示。

• 不要使用 string 查询，除非您真的想向您的用户展示 Lucene 查询字符串查询的所有功能（和脆弱性！）。

• 使用 match 查询，作为您的“通用目的”查询 -- Tire 在上面撒上一些糖，可以轻松创建 multi_match 查询等 p>

• 您的示例中的过滤器语法是正确的。当filter 方法在Tire 中被多次调用时，它会创建and 过滤器。

取消注释 Tire 日志配置（可能还有 ActiveRecord 日志），以查看代码在做什么。