ruby-on-rails - pg_search : ordering of "multisearchable" results

Question

我将 Rails 4.2.4 与 pg_search 1.0.5 一起使用。

class Advert < ActiveRecord::Base

  include PgSearch
  multisearchable :against => [:title, :body]

end

我想按 :created_at 对 pg_search 结果进行排序我的广告记录的日期。从逻辑上讲，在我看来，以下内容可以工作( :asc ):

> @pgs = PgSearch.multisearch('55948189').order(created_at: :asc)

PgSearch::Document Load (136.1ms)  SELECT "pg_search_documents".* FROM "pg_search_documents" INNER JOIN (SELECT "pg_search_documents"."id" AS pg_search_id, (ts_rank((to_tsvector('simple', coalesce("pg_search_documents"."content"::text, ''))), (to_tsquery('simple', ''' ' || '55948189' || ' ''')), 0)) AS rank FROM "pg_search_documents" WHERE (((to_tsvector('simple', coalesce("pg_search_documents"."content"::text, ''))) @@ (to_tsquery('simple', ''' ' || '55948189' || ' '''))))) AS pg_search_ce9b9dd18c5c0023f2116f ON "pg_search_documents"."id" = pg_search_ce9b9dd18c5c0023f2116f.pg_search_id  ORDER BY pg_search_ce9b9dd18c5c0023f2116f.rank DESC, "pg_search_documents"."id" ASC, "pg_search_documents"."created_at" ASC
=> #<ActiveRecord::Relation [

#<PgSearch::Document id: 3148, content: "Aleksandra | Tallinn | 55948189 Simpatichnaja i se...", searchable_id: 3148, searchable_type: "Advert", created_at: "2015-10-01 11:44:06", updated_at: "2015-10-01 11:44:30">, 
#<PgSearch::Document id: 3275, content: "Aleksandra | Tallinn | 55948189 Simpatichnaja i se...", searchable_id: 3275, searchable_type: "Advert", created_at: "2015-10-02 11:05:49", updated_at: "2015-10-02 11:28:48">]> 

但是相反的顺序( :desc )会产生相同的结果:

> @pgs = PgSearch.multisearch('55948189').order(created_at: :desc)

PgSearch::Document Load (108.4ms)  SELECT "pg_search_documents".* FROM "pg_search_documents" INNER JOIN (SELECT "pg_search_documents"."id" AS pg_search_id, (ts_rank((to_tsvector('simple', coalesce("pg_search_documents"."content"::text, ''))), (to_tsquery('simple', ''' ' || '55948189' || ' ''')), 0)) AS rank FROM "pg_search_documents" WHERE (((to_tsvector('simple', coalesce("pg_search_documents"."content"::text, ''))) @@ (to_tsquery('simple', ''' ' || '55948189' || ' '''))))) AS pg_search_ce9b9dd18c5c0023f2116f ON "pg_search_documents"."id" = pg_search_ce9b9dd18c5c0023f2116f.pg_search_id  ORDER BY pg_search_ce9b9dd18c5c0023f2116f.rank DESC, "pg_search_documents"."id" ASC, "pg_search_documents"."created_at" DESC
=> #<ActiveRecord::Relation [

#<PgSearch::Document id: 3148, content: "Aleksandra | Tallinn | 55948189 Simpatichnaja i se...", searchable_id: 3148, searchable_type: "Advert", created_at: "2015-10-01 11:44:06", updated_at: "2015-10-01 11:44:30">, 
#<PgSearch::Document id: 3275, content: "Aleksandra | Tallinn | 55948189 Simpatichnaja i se...", searchable_id: 3275, searchable_type: "Advert", created_at: "2015-10-02 11:05:49", updated_at: "2015-10-02 11:28:48">]>

谁能解释我如何通过 :created_at 对我的搜索结果进行排序日期？

更新 1 : 是否可以通过 pg_search固定结果的顺序没有任何方法可以通过“created_at”进行订购？

我现在正在更仔细地阅读文档并发现以下语句:“默认情况下，pg_search 根据可搜索文本和查询之间的 :tsearch 相似度对结果进行排名。要使用不同的排名算法，您可以将 :ranked_by 选项传递给 pg_search_scope .” (见 https://github.com/Casecommons/pg_search)

Answer 1

有一个简单的答案，但它不适用于“multisearchable”。

首先，我需要从“multisearchable”(适用于多个模型)更改为“pg_search_scope”(仅在单个模型中搜索)。

其次，我需要使用 :order_within_rank .由于结果都是搜索词的100%匹配，根据pg_search它们的排名相同。 . :order_within_rank作为决胜局给出次要的排名。

class Advert < ActiveRecord::Base

  include PgSearch
  pg_search_scope :search_by_full_advert, 
                  :against => [:title, :body],
                  :order_within_rank => "adverts.created_at DESC"

end