I am trying to create unique document sequence values for my document libraries across multiple sites. I'm creating a calculated field "DocumentID" that is based on timestamp and list ID value. Works great upon document upload. However, when updating the properties, ID is not available when editing properties - so the DocumentID field recalculates with the ID value as 00.
How can I keep my DocumentID from updating once the value was been set at creation time?
Why are you re-inventing the wheel?
Just activate the Document ID feature built into SharePoint.
This is a site collection-level feature, so you must activate the feature in the site collection’s root web Site Settings menu. It is located at: Site Settings —> Site Collection Features
Here is Microsoft’s documentation for this feature.
As for ensuring that the Document ID is rendered with a particular date - SharePoint stores that as metadata. (This is the already invented wheel I referenced above.)
Additional benefits:
There is one down-side for you: The internal name of the Document ID column generated by this feature is the same as the one you are already using: ‘DocumentID’. So you may have to delete your existing DocumentID column to accommodate this feature.
The solution we used was to create a flow script that takes the last two digits of the library item id (a sequential number) and use that as a suffix to hhmmss of create timestamp. It's not TRULY unique across the tenant, but highly probable to never be duplicated. (You have to drop a file on a library the exact same hour/minute/second of a given day AND it has to be the same sequence in the list (43rd document) in order to be duplicated. Very highly unlikely to happen. And if it does - site collection context will assist the seeker of the file to identify which one they are seeking. The flow must be copied and configured to every library that uses the tagging structure - which is unfortunate. This will create dozens of flows (we typically have less than 40 active projects) but a naming convention will facilitate management.
Not the best solution - but it's workable.
Under Site Settings, there's a feature where you can enable a unique identifier that will apply across all lists/libraries of your site. Now - that may not make them unique across your tenant - but - you have the ability to provide a prefix. So - if your prefix is unique for each site collection - you'll get a unique value across your tenant. The only down-side is the document ID can be up to 10 digits long, followed by the actual list ID sequence value. Add to that a prefix - and you've got a rather long and unwieldy document ID. But --- for what it's worth - it's absolutely unique across the tenant.
The Document ID Service only provides a unique ID per site collection. In SharePoint Online every site is its own site collection. Moving an item to another site collection would need the document ID service enabled on each site and the document would be given a new ID as its not maintained.
SharePoint Online also assigned a unique GUID to a file, but when moving to other site collections, this is also re-generated.
Using a flow to set the Documents file property "UniqueID" with a GUID sets the ID in the file itself, so if moved can be tracked and wont change (unless a use edits it, so make it read-only or a PDF.
You'll need to map the file property unique field as searchable managed metadata say "FileUniqueId" to retrieve it and as long as you have access to it can retrieve it directly from the search box FileUniqueId:{GUID}
