MediaWiki 1.43 DBAL compatibility

[osnard]

Setup

• SMW version: master branch at #f6b3855f
• MW version: 1.43.0-wmf.2 (pre-release)
• PHP version: 8.1.20 (fpm-fcgi)
• DB system (MySQL, Blazegraph, etc.) and version: 10.11.4-MariaDB-1:10.11.4+maria~ubu2204

Issue

During the Wikimedia Hackathon 2024, I tried to run the latest version of Semantic MediaWiki on a pre-release version of MediaWiki 1.43 (upcomming LTS). The goal was to identify issues and maybe provide patches right away. Unfortunately, the available time will not allow to provide a fix, therefore I document the issue here.

First: Installation (running maintenance/run.php update) and activation of the extension ran smoothly, No immediate error.

But when trying to access Special:Browse the API call with the parameters

action: smwbrowse
format: json
browse: subject
params: {"subject":"Main_Page","ns":0,"iw":"","subobject":"","options":{"dir":null,"lang":"en","group":null,"printable":null,"offset":null,"including":false,"showInverse":false,"showAll":true,"showGroup":true,"showSort":false,"api":true,"valuelistlimit.out":"30","valuelistlimit.in":"20"},"type":"html"}

failed with the error

Exception caught: Table name component contains unexpected quote or dot character

"Wikimedia\\Rdbms\\DBLanguageError at /includes/libs/rdbms/platform/SQLPlatform.php(1051)
from /includes/libs/rdbms/platform/SQLPlatform.php(1051)
#0 /includes/libs/rdbms/platform/SQLPlatform.php(991): Wikimedia\\Rdbms\\Platform\\SQLPlatform->extractTableNameComponents(string)
#1 /includes/libs/rdbms/platform/SQLPlatform.php(957): Wikimedia\\Rdbms\\Platform\\SQLPlatform->qualifiedTableComponents(string)
#2 /includes/libs/rdbms/platform/SQLPlatform.php(936): Wikimedia\\Rdbms\\Platform\\SQLPlatform->tableName(string)
#3 /includes/libs/rdbms/platform/SQLPlatform.php(837): Wikimedia\\Rdbms\\Platform\\SQLPlatform->tableNameWithAlias(string, string)
#4 /includes/libs/rdbms/platform/SQLPlatform.php(666): Wikimedia\\Rdbms\\Platform\\SQLPlatform->tableNamesWithIndexClauseOrJOIN(array, array, array, array)
#5 /includes/libs/rdbms/database/Database.php(3335): Wikimedia\\Rdbms\\Platform\\SQLPlatform->selectSQLText(string, string, string, string, array, array)
#6 /includes/libs/rdbms/database/DatabaseMySQL.php(730): Wikimedia\\Rdbms\\Database->selectSQLText(string, string, string, string, array, array)
#7 /includes/libs/rdbms/database/Database.php(1342): Wikimedia\\Rdbms\\DatabaseMySQL->selectSQLText(string, string, string, string, array, array)
#8 /includes/libs/rdbms/database/DBConnRef.php(126): Wikimedia\\Rdbms\\Database->select(string, string, string, string, array, array)
#9 /includes/libs/rdbms/database/DBConnRef.php(358): Wikimedia\\Rdbms\\DBConnRef->__call(string, array)
#10 /extensions/SemanticMediaWiki/src/MediaWiki/Connection/Database.php(247): Wikimedia\\Rdbms\\DBConnRef->select(string, string, string, string, array, array)
#11 /extensions/SemanticMediaWiki/src/SQLStore/EntityStore/TraversalPropertyLookup.php(97): SMW\\MediaWiki\\Connection\\Database->select(string, string, string, string, array)
#12 /extensions/SemanticMediaWiki/src/SQLStore/EntityStore/EntityLookup.php(437): SMW\\SQLStore\\EntityStore\\TraversalPropertyLookup->fetchFromTable(SMW\\SQLStore\\PropertyTableDefinition, SMW\\DIWikiPage, SMW\\RequestOptions)
#13 /extensions/SemanticMediaWiki/src/SQLStore/SQLStore.php(289): SMW\\SQLStore\\EntityStore\\EntityLookup->getInProperties(SMW\\DIWikiPage, SMW\\RequestOptions)
#14 /extensions/SemanticMediaWiki/src/MediaWiki/Specials/Browse/HtmlBuilder.php(876): SMW\\SQLStore\\SQLStore->getInProperties(SMW\\DIWikiPage, SMW\\RequestOptions)
#15 /extensions/SemanticMediaWiki/src/MediaWiki/Specials/Browse/HtmlBuilder.php(355): SMW\\MediaWiki\\Specials\\Browse\\HtmlBuilder->getInData()
#16 /extensions/SemanticMediaWiki/src/MediaWiki/Specials/Browse/HtmlBuilder.php(263): SMW\\MediaWiki\\Specials\\Browse\\HtmlBuilder->createHTML()
#17 /extensions/SemanticMediaWiki/src/MediaWiki/Api/Browse/SubjectLookup.php(107): SMW\\MediaWiki\\Specials\\Browse\\HtmlBuilder->buildHTML()
#18 /extensions/SemanticMediaWiki/src/MediaWiki/Api/Browse/SubjectLookup.php(69): SMW\\MediaWiki\\Api\\Browse\\SubjectLookup->buildHTML(array)
#19 /extensions/SemanticMediaWiki/src/MediaWiki/Api/Browse.php(268): SMW\\MediaWiki\\Api\\Browse\\SubjectLookup->lookup(array)
#20 /extensions/SemanticMediaWiki/src/MediaWiki/Api/Browse.php(71): SMW\\MediaWiki\\Api\\Browse->callSubjectLookup(array)
#21 /includes/api/ApiMain.php(1948): SMW\\MediaWiki\\Api\\Browse->execute()
#22 /includes/api/ApiMain.php(924): ApiMain->executeAction()
#23 /includes/api/ApiMain.php(895): ApiMain->executeActionWithErrorHandling()
#24 /includes/api/ApiEntryPoint.php(158): ApiMain->execute()
#25 /includes/MediaWikiEntryPoint.php(199): MediaWiki\\Api\\ApiEntryPoint->execute()
#26 /api.php(44): MediaWiki\\MediaWikiEntryPoint->run()

Apparently the code at

SemanticMediaWiki/src/SQLStore/EntityStore/TraversalPropertyLookup.php

Lines 96 to 102 in f6b3855

	$result = $connection->select(
	$from,
	' smw_title,smw_sortkey,smw_iw',
	$conditions,
	__METHOD__,
	$options
	);

gets called with

$from = "`smw_object_ids` INNER JOIN ( SELECT p_id FROM `smw_di_wikipage`  WHERE o_id=0  GROUP BY p_id ) AS t1 ON t1.p_id=smw_id"

which is not allowed in the MediaWiki 1.43 DBAL anymore.

Wikimedia engineer Ladsgroup recommended to use the new "query builder" (in this particular case SelectQueryBuilder, see https://www.mediawiki.org/wiki/Manual:Database_access#SelectQueryBuilder) implementation of MediaWiki.

I can not tell how much code in Semantic MediaWiki is actually affected by this, but there are ~27 files that contain the INNER JOIN syntax.

[osnard]

I have created the draft PR #5636
It does not work yet, but roughly shows the direction. I believe the task contains two main items:

1. Make new MW43 DBAL factory methods (new*QueryBuilder()) available from SMW\Connection\ConnectionRef or SMW\MediaWiki\Connection\Database
2. Rewrite all problematic queries (most likely the ones with an INNER JOIN on a subquery) to MW43 DBAL

[Nikerabbit]

FYI: SelectQueryBuilder was introduced long time ago: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/566127. It's only now that everything is getting migrated over. The other query builders or some special features have been introduced later.