https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=42412 --- Comment #2 from Djalel CHEFROUR <djalel.chefrour@univ-soukahras.dz> --- Thanks for your PS note. Indeed, MySQL 8.4+ does enforce key uniqueness on those Koha illrequests FK constraints. Though, I did not notice the issue while upgrading our DB from MySQL 8.0.4 to 8.4.7. But, a week ago, I saw those SQL failures (as in bug 39107) when I tried a fresh import of our DB dump (post-upgrade) to a new local MySQL 8.4.7 for development. I guess the MySQL guys did not enforce unique keys for existing constraints in their upgrade process (which is probably a wise decision for backwards compatibility). Luckily, those constraints in illrequest still exist in the backup dump and show up with SHOW CREATE TABLE Another factor that allowed me to doge a bullet is the fact that we don't use ILL for now (our illrequests table is empty). Hopefully, I am on the safe side for future Koha releases that will support SQL 8.4+ -- You are receiving this mail because: You are watching all bug changes. You are the assignee for the bug.