如何在 default_scope 中指定模型？

Question

我的模型Chapter has_many Pages，而这又只属于一个Chapter。我正在尝试执行以下连接：

Chapter.joins(:pages)

但是我收到了这个错误：

SQLite3::SQLException: ambiguous column name: created_at: SELECT "chapters".* FROM "chapters" INNER JOIN "pages" ON "pages"."chapter_id" = "chapters"."id" AND (created_at >= '2015-04-24 23:22:32.783941')
ActiveRecord::StatementInvalid: SQLite3::SQLException: ambiguous column name: created_at: SELECT "chapters".* FROM "chapters" INNER JOIN "pages" ON "pages"."chapter_id" = "chapters"."id" AND (created_at >= '2015-04-24 23:22:32.783941')

Page 具有以下默认范围：

default_scope { where('created_at >= ?', 7.days.ago) }

如果没有那个 default_scope，连接就可以工作。所以我认为我必须以某种方式在 default_scope 中指定page.created_at。有谁知道怎么做？

Answer 1

default_scope {
  where("pages.created_at >= ?", 7.days.ago)
}