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The Basics
- Nextcloud Server version (e.g., 29.x.x):
34.0.4
- Operating system and version (e.g., Ubuntu 24.04):
- Ubuntu 24.04.4 LTS
- PHP version (e.g, 8.3):
8.3
Summary of the issue you are facing:
Migration fails during occ upgrade with error
Exception: Database error when running migration 1006Date20180628111625 for app dav
Steps to replicate it (hint: details matter!):
This is happening in step 5 of Migrating from ownCloud — Nextcloud 35 Administration Manual.
An exception occurred while executing a query: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry ‘12-0-445347D3-6E31-4E7B-BB53-689DA531319F’ for key ‘oc_calendarobjects.calobjects_by_uid_index’
Update failed
As far as I could establish it looks like the issue is caused by Nextcloud trying to create an index for calendar entries resulting in a constraint violation. I checked the ID in the table and there are over 160 lines with that ID. Digging through the DB it became clear that these are all part of a series with 12 being the ID, 445347D3-6E31-4E7B-BB53-689DA531319F being the UID. This combination exists multiple times but the entries are distinguished by a unique URI representing the recurrences.
It looks that Nextcloud does not consider all three resulting in a primary key violation.
Question is whether there is any script or manual process that needs to be executed before, e.g. serializing the entries to become compatible with Nextcloud indexes?
Any ideas are more than welcome! Thanks!