附加文件时的 Rails ActiveStorage 范围 [英] Rails ActiveStorage scope for when file is attached

问题描述

使用 ActiveStorage 时，如何为附加文件创建范围.

例如:

类检查

我想要像 Check.has_attached_image 这样的东西，只返回存在附加图像的记录.

我知道 ActiveStorage 提供了一个 with_attached_image 范围.但这似乎不起作用:

<代码>irb(main):009:0>Check.with_attached_image.to_sql=>"SELECT \"checks\".* FROM \"checks\""

解决方案

范围 with_attached_image 的主要目的是避免 N+1 查询(在您的查询中包含附加的 blob).

要仅返回存在附加图像的记录，您可以在 Check 模型中创建一个范围，如下所示:

scope :has_attached_image, ->{ joins(image_attachment: :blob) }

评论更新:

scope :has_attached_image, ->{ joins(:image_attachment) }

When using ActiveStorage, how do you create a scope for when files are attached.

For example:

class Check < ActiveRecord::Base
  has_one_attached :image
end

I want something like Check.has_attached_image to return only records where there is an existing attached image.

I know that ActiveStorage provides a with_attached_image scope. But that doesn't seem to be working:

irb(main):009:0> Check.with_attached_image.to_sql => "SELECT \"checks\".* FROM \"checks\""

解决方案

Main purpose of the scope with_attached_image is to avoid N+1 queries (to include the attached blobs in your query).

To return only records where there is an existing attached image, you can create a scope in the Check model like this:

scope :has_attached_image, -> { joins(image_attachment: :blob) }

Update from comments:

scope :has_attached_image, -> { joins(:image_attachment) }

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