如何找到从2个多到多个关系的关联记录
如何找到从2个多到多个关系的关联记录
提问于 2013-11-11 07:55:46
我有以下模型
Business has many Categories through Categorizations
Category has many Businesses through Categorizations
Business has many Estates through Localizations
Estate has many Businesses through Localizations我怎样才能找到某一特定产业的所有业务类别？
@类别=从某一产业的业务中查找所有类别
回答 1
Stack Overflow用户
回答已采纳
发布于 2013-11-11 08:36:02
肯定有更简单的方法，但您可以尝试这样做：
@estate = Estate.find(1)
@estate.businesses.map {|business| business.categories}.flatten或
@estate = Estate.find(1)
@categories = Categories.where(id: @estate.businesses.pluck(:id))页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/19901388
复制相关文章
相似问题
腾讯云开发者
