说我们有模特

class MyFirstModel < ApplicationRecord
  has_one_attached :my_attachment
end

我们决定在第一篇文章中附上一些文件

MyFirstModel.first.my_attachment.attach(io: File.open("/path/to/my_first.file"), filename: "my_first.file")

现在我们来检查一下

blob = ActiveStorage::Blob.last

blob.key
# => "7zs2snslr8ehnhlcz0c7dzz96k98"

blob.filename.to_s
# => "my_first.file"

我们就能找到这个文件

active_storage_config = Rails.configuration.active_storage
storage_root_dir = active_storage_config.service_configurations[active_storage_config.service.to_s]["root"]

Dir[File.join(storage_root_dir, "**", "*", blob.key)]
# => ["/path_to_app/storage/7z/s2/7zs2snslr8ehnhlcz0c7dzz96k98"]

你可以定义一些方法

def find_filepath_by_blob(blob)
  active_storage_config = Rails.configuration.active_storage
  storage_root_dir = active_storage_config.service_configurations[active_storage_config.service.to_s]["root"]

  Dir[File.join(storage_root_dir, "**", "*", blob.key)].first
end

这样我们就能找到所有的文件

ActiveStorage::Attachment.includes(:blob).find_each do |attachment|
  blob = attachment.blob

  puts <<~INFO
    Attachment ID: #{attachment.id}
    Attachment model: #{attachment.record_type}
    Attachment model ID: #{attachment.record_id}
    Filepath: #{find_filepath_by_blob(blob)}
    Filename: #{blob.filename}

  INFO
end

# will print
#
# Attachment ID: 1
# Attachment model: MyFirstModel
# Attachment model ID: 1
# Filepath: /path_to_app/storage/7z/s2/7zs2snslr8ehnhlcz0c7dzz96k98
# Filename: my_first.file
#
# Attachment ID: 3
# Attachment model: MyOtherModel
# Attachment model ID: 22
# Filepath: /path_to_app/storage/sv/yb/svybg3pr5kme2uxzkiupjqykxrr5
# Filename: some.file

当然，你可以做你想要的，而不是打印这些信息。例如上传到一些云