fix(QueryBuilder): Restrict identifier length to 30 characters due to Oracle limitations

[provokateurin]

Summary

According to https://docs.nextcloud.com/server/latest/admin_manual/installation/system_requirements.html we still support Oracle versions <12.2.
https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/Database-Object-Names-and-Qualifiers.html says:
If COMPATIBLE is set to a value of 12.2 or higher, then names must be from 1 to 128 bytes long and If COMPATIBLE is set to a value lower than 12.2, then names must be from 1 to 30 bytes long.
This means we must prevent any identifier with more than 30 characters as long as we support Oracle <12.2.

This check should also be extended to table names and schema names, but I'm not sure how to do that best.
I found this due to https://github.com/nextcloud/groupfolders/actions/runs/10960223441/job/30434816204 (which tests against Oracle 11) which triggers this query:

 SELECT `g`.`folder_id`,
       `g`.`group_id`,
       `g`.`circle_id`,
       `g`.`permissions`,
       `hp_cc`.`unique_id`                 AS `hp_cc_unique_id`,
       `hp_cc`.`name`                      AS `hp_cc_name`,
       `hp_cc`.`display_name`              AS `hp_cc_display_name`,
       `hp_cc`.`sanitized_name`            AS `hp_cc_sanitized_name`,
       `hp_cc`.`source`                    AS `hp_cc_source`,
       `hp_cc`.`description`               AS `hp_cc_description`,
       `hp_cc`.`settings`                  AS `hp_cc_settings`,
       `hp_cc`.`config`                    AS `hp_cc_config`,
       `hp_cc`.`contact_addressbook`       AS `hp_cc_contact_addressbook`,
       `hp_cc`.`contact_groupname`         AS `hp_cc_contact_groupname`,
       `hp_cc`.`creation`                  AS `hp_cc_creation`,
       `hp_cc_wn`.`circle_id`              AS `hp_cc_wn_circle_id`,
       `hp_cc_wn`.`member_id`              AS `hp_cc_wn_member_id`,
       `hp_cc_wn`.`single_id`              AS `hp_cc_wn_single_id`,
       `hp_cc_wn`.`user_id`                AS `hp_cc_wn_user_id`,
       `hp_cc_wn`.`instance`               AS `hp_cc_wn_instance`,
       `hp_cc_wn`.`user_type`              AS `hp_cc_wn_user_type`,
       `hp_cc_wn`.`level`                  AS `hp_cc_wn_level`,
       `hp_cc_wn`.`status`                 AS `hp_cc_wn_status`,
       `hp_cc_wn`.`note`                   AS `hp_cc_wn_note`,
       `hp_cc_wn`.`contact_id`             AS `hp_cc_wn_contact_id`,
       `hp_cc_wn`.`cached_name`            AS `hp_cc_wn_cached_name`,
       `hp_cc_wn`.`cached_update`          AS `hp_cc_wn_cached_update`,
       `hp_cc_wn`.`contact_meta`           AS `hp_cc_wn_contact_meta`,
       `hp_cc_wn`.`joined`                 AS `hp_cc_wn_joined`,
       `hp_cc_wn_on`.`unique_id`           AS `hp_cc_wn_on_unique_id`,
       `hp_cc_wn_on`.`name`                AS `hp_cc_wn_on_name`,
       `hp_cc_wn_on`.`display_name`        AS `hp_cc_wn_on_display_name`,
       `hp_cc_wn_on`.`sanitized_name`      AS `hp_cc_wn_on_sanitized_name`,
       `hp_cc_wn_on`.`source`              AS `hp_cc_wn_on_source`,
       `hp_cc_wn_on`.`description`         AS `hp_cc_wn_on_description`,
       `hp_cc_wn_on`.`settings`            AS `hp_cc_wn_on_settings`,
       `hp_cc_wn_on`.`config`              AS `hp_cc_wn_on_config`,
       `hp_cc_wn_on`.`contact_addressbook` AS `hp_cc_wn_on_contact_addressbook`,
       `hp_cc_wn_on`.`contact_groupname`   AS `hp_cc_wn_on_contact_groupname`,
       `hp_cc_wn_on`.`creation`            AS `hp_cc_wn_on_creation`
FROM   `*prefix*group_folders_groups` `g`
       LEFT JOIN `*prefix*circles_circle` `hp_cc`
              ON `hp_cc`.`unique_id` = `g`.`circle_id`
       LEFT JOIN `*prefix*circles_member` `hp_cc_wn`
              ON ( `hp_cc_wn`.`circle_id` = `hp_cc`.`unique_id` )
                 AND ( `hp_cc_wn`.`level` = :dcValue1 )
       LEFT JOIN `*prefix*circles_circle` `hp_cc_wn_on`
              ON `hp_cc_wn_on`.`unique_id` = `hp_cc_wn`.`single_id`

where hp_cc_wn_on_contact_addressbook is 31 characters.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[provokateurin]

/backport to stable30

[provokateurin]

/backport to stable29

[provokateurin]

/backport to stable28

[come-nc]

This does not fix the bug but ensures it crashes on all DB, right?
Is there no way to magically fix the query instead, ideally in a class specific to OCI? I see we have Adapter, ExpressionBuilder and FuncitonBuilder specifc to OCI.

If we keep this as-is, what would the fix look like in the calling method?

[provokateurin]

This does not fix the bug but ensures it crashes on all DB, right?

It doesn't crash, it just logs an error. It will fail on Oracle when the query is executed eventually.

Is there no way to magically fix the query instead, ideally in a class specific to OCI? I see we have Adapter, ExpressionBuilder and FuncitonBuilder specifc to OCI.

I don't think we can magically fix this as the code receiving the results relies on the exact names.

If we keep this as-is, what would the fix look like in the calling method?

The aliases just need to be shorter. For example Circles adds a ton of prefixes to the name so I think for that case we could maybe drop some of them.
In theory we could still have a columns with names longer than 30 chars, but those need to be prevented at creation time.

[come-nc]

Okay I missed that the Exception is not thrown but only logged.

[nickvergessen]

This check should also be extended to table names and schema names, but I'm not sure how to do that best.

We do this already:

server/lib/private/DB/MigrationService.php

Lines 528 to 550 in 9836e9b

	/**
	* Naming constraints:
	* - Tables names must be 30 chars or shorter (27 + oc_ prefix)
	* - Column names must be 30 chars or shorter
	* - Index names must be 30 chars or shorter
	* - Sequence names must be 30 chars or shorter
	* - Primary key names must be set or the table name 23 chars or shorter
	*
	* Data constraints:
	* - Tables need a primary key (Not specific to Oracle, but required for performant clustering support)
	* - Columns with "NotNull" can not have empty string as default value
	* - Columns with "NotNull" can not have number 0 as default value
	* - Columns with type "bool" (which is in fact integer of length 1) can not be "NotNull" as it can not store 0/false
	* - Columns with type "string" can not be longer than 4.000 characters, use "text" instead
	*
	* @see https://github.com/nextcloud/documentation/blob/master/developer_manual/basics/storage/database.rst
	*
	* @param Schema $sourceSchema
	* @param Schema $targetSchema
	* @param int $prefixLength
	* @throws \Doctrine\DBAL\Exception
	*/
	public function ensureOracleConstraints(Schema $sourceSchema, Schema $targetSchema, int $prefixLength) {