Google Drive API：基于ID替换文件并保留原文件ID的方案问询

Great question—this is a super common scenario when you’ve got integrations or links tied to a specific file ID that you can’t change. The good news is you don’t need to download File B and re-upload it to File A. Google Drive API has a straightforward way to handle this with the Files: update endpoint, and you can even optimize it to avoid external bandwidth usage if File B is already in Drive.

Two Efficient Approaches #

1. When File B is already in Google Drive (same account or shared to you) #

This is the most efficient method because Drive can handle the content copy internally—no need to shuttle data to your server first:

• First, fetch File B’s raw content using the Files: get endpoint with the alt=media parameter. This returns the file’s actual data stream.
• Then, pass that stream directly as the request body to the Files: update endpoint, targeting File A’s ID and using the uploadType=media parameter.

If you’re using an official client library (like Python’s google-api-python-client or Java’s Drive SDK), the library will handle this internal stream transfer automatically—you just need to specify the source file ID (B) and target file ID (A), and it takes care of the rest.

2. When File B is on your local machine or external storage #

In this case, you can skip the download step entirely. Just call Files: update with File A’s ID as the target, and pass File B’s data stream directly as the media request body (again with uploadType=media). This replaces File A’s content in a single API call, no extra steps needed.

Key Things to Keep in Mind #

• Make sure your API service account or user account has edit access to File A and read access to File B (if it’s in Drive).
• If File A is a Google-native format (Docs, Sheets, Slides), you’ll need to set convert=true in the Files: update request if File B is a different format (e.g., a .docx replacing a Google Doc). This ensures the content is converted properly while retaining File A’s ID and native format.
• Replacing content via Files: update preserves File A’s ID, sharing permissions, version history, and all other metadata—exactly what you need.

Why drive.copy Doesn’t Work #

As you noted, Files: copy creates an entirely new file with a new ID, so it’s useless for this use case. We need to modify the existing file directly, which is exactly what Files: update is designed for.

内容的提问来源于stack exchange，提问作者corycorycory