Upgrade from 20 to 21 fails with dbalexception "Unknown column type "json_array" requested"


after updating today successfully to latest version of 20 I also wanted to upgrade to 21.

After the upgrade via web gui failed with the same following message, I started occ with verbosity on debug.

2021-10-24T09:36:32+00:00 Setting log level to debug
2021-10-24T09:36:32+00:00 Repair step: Repair MySQL collation
2021-10-24T09:36:32+00:00 Repair info: All tables already have the correct collation → nothing to do
2021-10-24T09:36:32+00:00 Repair step: Repair SQLite autoincrement
2021-10-24T09:36:32+00:00 Repair step: Copy data from accounts table when migrating from ownCloud
2021-10-24T09:36:32+00:00 OC\DB\Exceptions\DbalException: Unknown column type “json_array” requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a list of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this error occurs during database introspection then you might have forgotten to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getMappedDatabaseTypes(). If the type name is empty you might have a problem with the cache or forgot some mapping information.
2021-10-24T09:36:32+00:00 Update failed
2021-10-24T09:36:32+00:00 Maintenance mode is kept active
2021-10-24T09:36:32+00:00 Resetting log level

Any ideas or maybe there are others with the same problem? I am disabling apps one after the other atm.

Best and thanks,

So if I understand correctly, we are in the step of migrating data from nextcloud database version 20 to version 21 and the database framework doctrince is tellings us, that json_array is requested from our applications running code and our database or at least the framework doesn’t supports the json_array column type.

MariaDB Server Version: 10.3.21
Php 7.4
Source is Nextcloud
Target is Nextcloud 21.0.5

Ok apparently there was on old table of the face recognition plugin, that had the unknown/old json_array type in its schema. I deleted the plugin and now upgraded the whole instance successfully.

So its solved.