Question

我有一种搜索方法，我希望为用户提供排除{I}搜索模型的选项，该搜索具有特定主题。 Cases模型与Search有两个独立的多对多关系，设置如下：

Topics

要搜索包含某些主题的案例，我使用了此代码。

class Search < ActiveRecord::Base
  include ViewersHelper

  has_many :included_topics, through: :including_topics, source: :topic
  has_many :excluded_topics, through: :excluding_topics, source: :topic
  has_many :including_topics
  has_many :excluding_topics

此查询的相反之处是使排除的主题有效吗？

根据this question，我尝试了以下内容：

  ids = included_topics.pluck(:id)
  cases = cases.includes(:topics).where('topics.id' => ids)

但是rails会从该查询中给出以下错误：

  ids = excludes_topics.pluck(:id)
  cases = cases.includes(:topics).where('topics.id NOT IN (?)', ids)

第6行只是在引用中执行搜索的ActiveRecord::StatementInvalid in Searches#show Showing ../app/views/searches/show.html.erb where line #6 raised: SQLite3::SQLException: no such column: topics.id: SELECT "cases".* FROM "cases" WHERE (topics.id NOT IN (2)) LIMIT 20 OFFSET 0变量的第一行

Answer 1

您可以使用

ids = excludes_topics.pluck(:id) cases = Case.joins(:topics).where('topics.id NOT IN (?)', ids)

Answer 2

这是我使用两个查询创建的解决方案：

  ids = excludes_topics.pluck(:id)
  included_cases_ids = Case.all.includes(:topics).where('topics.id' => ids).pluck(:id)
  cases = cases.where.not('id' => included_cases_ids)

Ruby on Rails - 排除标签的范围

2 个答案: