ruby-on-rails - 在集合和祖 parent 上使用 .where 创建范围

Question

我有三个具有祖 parent 、 parent 、 child 关系的模型:Organization、Category、Post。

我正在尝试在我的 Post 模型中创建一个范围，首先在传递的集合上使用 where，然后在祖 parent 上使用:

scope :ready, -> {
  where("next_setup_at < ?", DateTime.current)
    .joins(category: :organization)
    .where("organizations.active = ?", true)
}

但是 Postgres 给我一个错误:

ActiveRecord::StatementInvalid: PG::AmbiguousColumn: ERROR: column reference "next_setup_at" is ambiguous LINE 1: ...zations"."id" = "categories"."organization_id" WHERE (next_setup... ^

: SELECT "posts".* FROM "posts" INNER JOIN "categories" ON "categories"."id" = "posts"."category_id" INNER JOIN "organizations" ON "organizations"."id" = "categories"."organization_id" WHERE (next_setup_at < '2016-03-22 15:57:19.971887') AND (organizations.active = 't')

Answer 1

看看您的 .where 子句。第二个很好地定义了要查询的列。

where("organizations.active = ?", true)

第一个没有。

where("next_setup_at < ?", DateTime.current)

您必须定义 next_setup_at 列引用的表。导致

where("posts.next_setup_at < ?", DateTime.current)

进一步完善

您可以像这样轻松地指定要在纯 ActiveRecord 中引用的表:

where(posts: {next_setup_at: DateTime.current}, categories: {active: true})