From 1b58c93a437ed1691bb5b6a7edcd512da49adbe4 Mon Sep 17 00:00:00 2001
From: Carl Schwan <carlschwan@kde.org>
Date: Fri, 23 Jan 2026 16:55:54 +0100
Subject: [PATCH] refactor(QueryBuilder): Properly type the query builder

Signed-off-by: Carl Schwan <carlschwan@kde.org>
---
 build/psalm-baseline.xml                      |  19 -
 .../DB/QueryBuilder/ExtendedQueryBuilder.php  | 175 ++--
 .../FunctionBuilder/FunctionBuilder.php       |   8 +
 .../Partitioned/PartitionedQueryBuilder.php   |  69 +-
 lib/private/DB/QueryBuilder/QueryBuilder.php  | 916 +++---------------
 lib/private/DB/QueryBuilder/QuoteHelper.php   |  18 +-
 .../Sharded/ShardedQueryBuilder.php           | 123 ++-
 lib/private/Files/Cache/CacheQueryBuilder.php |  10 +-
 lib/private/Group/Database.php                |   2 +-
 .../OpenMetrics/Exporters/ActiveUsers.php     |   2 +-
 .../DB/QueryBuilder/IFunctionBuilder.php      |  11 +
 lib/public/DB/QueryBuilder/IQueryBuilder.php  | 174 ++--
 12 files changed, 463 insertions(+), 1064 deletions(-)

diff --git a/build/psalm-baseline.xml b/build/psalm-baseline.xml
index 371f575b9a25e..a752fbf87f72f 100644
--- a/build/psalm-baseline.xml
+++ b/build/psalm-baseline.xml
@@ -3520,25 +3520,6 @@
       <code><![CDATA[$params['collation']]]></code>
     </InvalidArrayOffset>
   </file>
-  <file src="lib/private/DB/QueryBuilder/QueryBuilder.php">
-    <InvalidNullableReturnType>
-      <code><![CDATA[string]]></code>
-    </InvalidNullableReturnType>
-    <NullableReturnStatement>
-      <code><![CDATA[$alias]]></code>
-    </NullableReturnStatement>
-    <ParamNameMismatch>
-      <code><![CDATA[$selects]]></code>
-    </ParamNameMismatch>
-  </file>
-  <file src="lib/private/DB/QueryBuilder/QuoteHelper.php">
-    <InvalidNullableReturnType>
-      <code><![CDATA[string]]></code>
-    </InvalidNullableReturnType>
-    <NullableReturnStatement>
-      <code><![CDATA[$string]]></code>
-    </NullableReturnStatement>
-  </file>
   <file src="lib/private/DateTimeFormatter.php">
     <FalsableReturnStatement>
       <code><![CDATA[$l->l($type, $timestamp, [
diff --git a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
index 9230c55c28c86..eba22583ff780 100644
--- a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php
@@ -9,284 +9,349 @@
 namespace OC\DB\QueryBuilder;
 
 use OCP\DB\IResult;
+use OCP\DB\QueryBuilder\ICompositeExpression;
+use OCP\DB\QueryBuilder\IExpressionBuilder;
+use OCP\DB\QueryBuilder\IFunctionBuilder;
+use OCP\DB\QueryBuilder\ILiteral;
+use OCP\DB\QueryBuilder\IParameter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\DB\QueryBuilder\IQueryFunction;
 use OCP\IDBConnection;
+use Override;
 
 /**
  * Base class for creating classes that extend the builtin query builder
  */
 abstract class ExtendedQueryBuilder implements IQueryBuilder {
 	public function __construct(
-		protected IQueryBuilder $builder,
+		protected readonly IQueryBuilder $builder,
 	) {
 	}
 
-	public function automaticTablePrefix($enabled) {
+	#[Override]
+	public function automaticTablePrefix(bool $enabled): void {
 		$this->builder->automaticTablePrefix($enabled);
-		return $this;
 	}
 
-	public function expr() {
+	#[Override]
+	public function expr(): IExpressionBuilder {
 		return $this->builder->expr();
 	}
 
-	public function func() {
+	#[Override]
+	public function func(): IFunctionBuilder {
 		return $this->builder->func();
 	}
 
-	public function getType() {
+	#[Override]
+	public function getType(): int {
 		return $this->builder->getType();
 	}
 
-	public function getConnection() {
+	#[Override]
+	public function getConnection(): IDBConnection {
 		return $this->builder->getConnection();
 	}
 
-	public function getState() {
+	#[Override]
+	public function getState(): int {
 		return $this->builder->getState();
 	}
 
-	public function getSQL() {
+	#[Override]
+	public function getSQL(): string {
 		return $this->builder->getSQL();
 	}
 
-	public function setParameter($key, $value, $type = null) {
+	#[Override]
+	public function setParameter(string|int $key, mixed $value, string|null|int $type = null): self {
 		$this->builder->setParameter($key, $value, $type);
 		return $this;
 	}
 
-	public function setParameters(array $params, array $types = []) {
+	#[Override]
+	public function setParameters(array $params, array $types = []): self {
 		$this->builder->setParameters($params, $types);
 		return $this;
 	}
 
-	public function getParameters() {
+	#[Override]
+	public function getParameters(): array {
 		return $this->builder->getParameters();
 	}
 
-	public function getParameter($key) {
+	#[Override]
+	public function getParameter(int|string $key): mixed {
 		return $this->builder->getParameter($key);
 	}
 
-	public function getParameterTypes() {
+	#[Override]
+	public function getParameterTypes(): array {
 		return $this->builder->getParameterTypes();
 	}
 
-	public function getParameterType($key) {
+	#[Override]
+	public function getParameterType(int|string $key): mixed {
 		return $this->builder->getParameterType($key);
 	}
 
-	public function setFirstResult($firstResult) {
+	#[Override]
+	public function setFirstResult(int $firstResult): self {
 		$this->builder->setFirstResult($firstResult);
 		return $this;
 	}
 
-	public function getFirstResult() {
+	#[Override]
+	public function getFirstResult(): int {
 		return $this->builder->getFirstResult();
 	}
 
-	public function setMaxResults($maxResults) {
+	#[Override]
+	public function setMaxResults(?int $maxResults): self {
 		$this->builder->setMaxResults($maxResults);
 		return $this;
 	}
 
-	public function getMaxResults() {
+	#[Override]
+	public function getMaxResults(): ?int {
 		return $this->builder->getMaxResults();
 	}
 
-	public function select(...$selects) {
+	#[Override]
+	public function select(...$selects): self {
 		$this->builder->select(...$selects);
 		return $this;
 	}
 
-	public function selectAlias($select, $alias) {
+	#[Override]
+	public function selectAlias(string|IQueryFunction|IParameter $select, string $alias): self {
 		$this->builder->selectAlias($select, $alias);
 		return $this;
 	}
 
-	public function selectDistinct($select) {
+	#[Override]
+	public function selectDistinct(string|array $select): self {
 		$this->builder->selectDistinct($select);
 		return $this;
 	}
 
-	public function addSelect(...$select) {
-		$this->builder->addSelect(...$select);
+	#[Override]
+	public function addSelect(...$selects): self {
+		$this->builder->addSelect(...$selects);
 		return $this;
 	}
 
-	public function delete($delete = null, $alias = null) {
+	#[Override]
+	public function delete(string $delete, ?string $alias = null): self {
 		$this->builder->delete($delete, $alias);
 		return $this;
 	}
 
-	public function update($update = null, $alias = null) {
+	#[Override]
+	public function update(string $update, ?string $alias = null): self {
 		$this->builder->update($update, $alias);
 		return $this;
 	}
 
-	public function insert($insert = null) {
+	#[Override]
+	public function insert(string $insert): self {
 		$this->builder->insert($insert);
 		return $this;
 	}
 
-	public function from($from, $alias = null) {
+	#[Override]
+	public function from(string|IQueryFunction $from, ?string $alias = null): self {
 		$this->builder->from($from, $alias);
 		return $this;
 	}
 
-	public function join($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function join(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self {
 		$this->builder->join($fromAlias, $join, $alias, $condition);
 		return $this;
 	}
 
-	public function innerJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function innerJoin($fromAlias, $join, $alias, $condition = null): self {
 		$this->builder->innerJoin($fromAlias, $join, $alias, $condition);
 		return $this;
 	}
 
-	public function leftJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function leftJoin($fromAlias, $join, $alias, $condition = null): self {
 		$this->builder->leftJoin($fromAlias, $join, $alias, $condition);
 		return $this;
 	}
 
-	public function rightJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function rightJoin($fromAlias, $join, $alias, $condition = null): self {
 		$this->builder->rightJoin($fromAlias, $join, $alias, $condition);
 		return $this;
 	}
 
-	public function set($key, $value) {
+	#[Override]
+	public function set($key, $value): self {
 		$this->builder->set($key, $value);
 		return $this;
 	}
 
-	public function where(...$predicates) {
+	#[Override]
+	public function where(...$predicates): self {
 		$this->builder->where(...$predicates);
 		return $this;
 	}
 
-	public function andWhere(...$where) {
+	#[Override]
+	public function andWhere(...$where): self {
 		$this->builder->andWhere(...$where);
 		return $this;
 	}
 
-	public function orWhere(...$where) {
+	#[Override]
+	public function orWhere(...$where): self {
 		$this->builder->orWhere(...$where);
 		return $this;
 	}
 
-	public function groupBy(...$groupBys) {
+	#[Override]
+	public function groupBy(...$groupBys): self {
 		$this->builder->groupBy(...$groupBys);
 		return $this;
 	}
 
-	public function addGroupBy(...$groupBy) {
+	#[Override]
+	public function addGroupBy(...$groupBy): self {
 		$this->builder->addGroupBy(...$groupBy);
 		return $this;
 	}
 
-	public function setValue($column, $value) {
+	#[Override]
+	public function setValue(string $column, IParameter|IQueryFunction|string $value): self {
 		$this->builder->setValue($column, $value);
 		return $this;
 	}
 
-	public function values(array $values) {
+	#[Override]
+	public function values(array $values): self {
 		$this->builder->values($values);
 		return $this;
 	}
 
-	public function having(...$having) {
+	#[Override]
+	public function having(...$having): self {
 		$this->builder->having(...$having);
 		return $this;
 	}
 
-	public function andHaving(...$having) {
+	#[Override]
+	public function andHaving(...$having): self {
 		$this->builder->andHaving(...$having);
 		return $this;
 	}
 
-	public function orHaving(...$having) {
+	#[Override]
+	public function orHaving(...$having): self {
 		$this->builder->orHaving(...$having);
 		return $this;
 	}
 
-	public function orderBy($sort, $order = null) {
+	#[Override]
+	public function orderBy(string|ILiteral|IParameter|IQueryFunction $sort, ?string $order = null): self {
 		$this->builder->orderBy($sort, $order);
 		return $this;
 	}
 
-	public function addOrderBy($sort, $order = null) {
+	#[Override]
+	public function addOrderBy(string|ILiteral|IParameter|IQueryFunction $sort, ?string $order = null): self {
 		$this->builder->addOrderBy($sort, $order);
 		return $this;
 	}
 
-	public function getQueryPart($queryPartName) {
+	#[Override]
+	public function getQueryPart(string $queryPartName): mixed {
 		return $this->builder->getQueryPart($queryPartName);
 	}
 
-	public function getQueryParts() {
+	#[Override]
+	public function getQueryParts(): array {
 		return $this->builder->getQueryParts();
 	}
 
-	public function resetQueryParts($queryPartNames = null) {
+	#[Override]
+	public function resetQueryParts(?array $queryPartNames = null): self {
 		$this->builder->resetQueryParts($queryPartNames);
 		return $this;
 	}
 
-	public function resetQueryPart($queryPartName) {
+	#[Override]
+	public function resetQueryPart(string $queryPartName): self {
 		$this->builder->resetQueryPart($queryPartName);
 		return $this;
 	}
 
-	public function createNamedParameter($value, $type = self::PARAM_STR, $placeHolder = null) {
+	#[Override]
+	public function createNamedParameter(mixed $value, mixed $type = self::PARAM_STR, $placeHolder = null): IParameter {
 		return $this->builder->createNamedParameter($value, $type, $placeHolder);
 	}
 
-	public function createPositionalParameter($value, $type = self::PARAM_STR) {
+	#[Override]
+	public function createPositionalParameter(mixed $value, mixed $type = self::PARAM_STR): IParameter {
 		return $this->builder->createPositionalParameter($value, $type);
 	}
 
-	public function createParameter($name) {
+	#[Override]
+	public function createParameter(string $name): IParameter {
 		return $this->builder->createParameter($name);
 	}
 
-	public function createFunction($call) {
+	#[Override]
+	public function createFunction(string $call): IQueryFunction {
 		return $this->builder->createFunction($call);
 	}
 
+	#[Override]
 	public function getLastInsertId(): int {
 		return $this->builder->getLastInsertId();
 	}
 
-	public function getTableName($table) {
+	#[Override]
+	public function getTableName(string|IQueryFunction $table): string {
 		return $this->builder->getTableName($table);
 	}
 
-	public function getColumnName($column, $tableAlias = '') {
+	#[Override]
+	public function getColumnName(string $column, string $tableAlias = ''): string {
 		return $this->builder->getColumnName($column, $tableAlias);
 	}
 
+	#[Override]
 	public function executeQuery(?IDBConnection $connection = null): IResult {
 		return $this->builder->executeQuery($connection);
 	}
 
+	#[Override]
 	public function executeStatement(?IDBConnection $connection = null): int {
 		return $this->builder->executeStatement($connection);
 	}
 
+	#[Override]
 	public function hintShardKey(string $column, mixed $value, bool $overwrite = false): self {
 		$this->builder->hintShardKey($column, $value, $overwrite);
 		return $this;
 	}
 
+	#[Override]
 	public function runAcrossAllShards(): self {
 		$this->builder->runAcrossAllShards();
 		return $this;
 	}
 
+	#[Override]
 	public function getOutputColumns(): array {
 		return $this->builder->getOutputColumns();
 	}
 
+	#[Override]
 	public function prefixTableName(string $table): string {
 		return $this->builder->prefixTableName($table);
 	}
diff --git a/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php b/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php
index 48dc1da6330b8..ce4dff6a2adb5 100644
--- a/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php
+++ b/lib/private/DB/QueryBuilder/FunctionBuilder/FunctionBuilder.php
@@ -10,6 +10,8 @@
 use OC\DB\QueryBuilder\QueryFunction;
 use OC\DB\QueryBuilder\QuoteHelper;
 use OCP\DB\QueryBuilder\IFunctionBuilder;
+use OCP\DB\QueryBuilder\ILiteral;
+use OCP\DB\QueryBuilder\IParameter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\DB\QueryBuilder\IQueryFunction;
 use OCP\IDBConnection;
@@ -78,6 +80,12 @@ public function count($count = '', $alias = ''): IQueryFunction {
 		return new QueryFunction('COUNT(' . $quotedName . ')' . $alias);
 	}
 
+	public function countDistinct(string|ILiteral|IParameter|IQueryFunction $count = '', string $alias = ''): IQueryFunction {
+		$alias = !empty($alias) ? (' AS ' . $this->helper->quoteColumnName($alias)) : '';
+		$quotedName = $count === '' ? '*' : $this->helper->quoteColumnName($count);
+		return new QueryFunction('COUNT(DISTINCT ' . $quotedName . ')' . $alias);
+	}
+
 	public function octetLength($field, $alias = ''): IQueryFunction {
 		$alias = $alias ? (' AS ' . $this->helper->quoteColumnName($alias)) : '';
 		$quotedName = $this->helper->quoteColumnName($field);
diff --git a/lib/private/DB/QueryBuilder/Partitioned/PartitionedQueryBuilder.php b/lib/private/DB/QueryBuilder/Partitioned/PartitionedQueryBuilder.php
index 7750ce5056a8d..d3936a9f9513c 100644
--- a/lib/private/DB/QueryBuilder/Partitioned/PartitionedQueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/Partitioned/PartitionedQueryBuilder.php
@@ -14,6 +14,7 @@
 use OC\DB\QueryBuilder\Sharded\ShardConnectionManager;
 use OC\DB\QueryBuilder\Sharded\ShardedQueryBuilder;
 use OCP\DB\IResult;
+use OCP\DB\QueryBuilder\IParameter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\DB\QueryBuilder\IQueryFunction;
 use OCP\IDBConnection;
@@ -41,7 +42,7 @@ class PartitionedQueryBuilder extends ShardedQueryBuilder {
 	/** @var list<PartitionSplit> */
 	private array $partitions = [];
 
-	/** @var array{'select': string|array, 'alias': ?string}[] */
+	/** @var array{'select': string|IQueryFunction|IParameter, 'alias': ?string}[] */
 	private array $selects = [];
 	private ?PartitionSplit $mainPartition = null;
 	private bool $hasPositionalParameter = false;
@@ -75,7 +76,7 @@ private function newQuery(): IQueryBuilder {
 	}
 
 	// we need to save selects until we know all the table aliases
-	public function select(...$selects) {
+	public function select(...$selects): self {
 		if (count($selects) === 1 && is_array($selects[0])) {
 			$selects = $selects[0];
 		}
@@ -84,15 +85,13 @@ public function select(...$selects) {
 		return $this;
 	}
 
-	public function addSelect(...$select) {
-		$select = array_map(function ($select) {
-			return ['select' => $select, 'alias' => null];
-		}, $select);
-		$this->selects = array_merge($this->selects, $select);
+	public function addSelect(...$selects): self {
+		$selects = array_map(static fn ($select) => ['select' => $select, 'alias' => null], $selects);
+		$this->selects = array_merge($this->selects, $selects);
 		return $this;
 	}
 
-	public function selectAlias($select, $alias) {
+	public function selectAlias(string|IQueryFunction|IParameter $select, string $alias): self {
 		$this->selects[] = ['select' => $select, 'alias' => $alias];
 		return $this;
 	}
@@ -101,9 +100,6 @@ public function selectAlias($select, $alias) {
 	 * Ensure that a column is being selected by the query
 	 *
 	 * This is mainly used to ensure that the returned rows from both sides of a partition contains the columns of the join predicate
-	 *
-	 * @param string|IQueryFunction $column
-	 * @return void
 	 */
 	private function ensureSelect(string|IQueryFunction $column, ?string $alias = null): void {
 		$checkColumn = $alias ?: $column;
@@ -190,14 +186,15 @@ private function getPartition(string $table): ?PartitionSplit {
 		return null;
 	}
 
-	public function from($from, $alias = null) {
+	public function from($from, $alias = null): self {
 		if (is_string($from) && $partition = $this->getPartition($from)) {
 			$this->mainPartition = $partition;
 			if ($alias) {
 				$this->mainPartition->addAlias($from, $alias);
 			}
 		}
-		return parent::from($from, $alias);
+		parent::from($from, $alias);
+		return $this;
 	}
 
 	public function innerJoin($fromAlias, $join, $alias, $condition = null): self {
@@ -281,11 +278,14 @@ public function join($fromAlias, $join, $alias, $condition = null, $joinMode = P
 		} else {
 			// join within the main db or a partition
 			if ($joinMode === PartitionQuery::JOIN_MODE_INNER) {
-				return parent::innerJoin($fromAlias, $join, $alias, $condition);
+				parent::innerJoin($fromAlias, $join, $alias, $condition);
+				return $this;
 			} elseif ($joinMode === PartitionQuery::JOIN_MODE_LEFT) {
-				return parent::leftJoin($fromAlias, $join, $alias, $condition);
+				parent::leftJoin($fromAlias, $join, $alias, $condition);
+				return $this;
 			} elseif ($joinMode === PartitionQuery::JOIN_MODE_RIGHT) {
-				return parent::rightJoin($fromAlias, $join, $alias, $condition);
+				parent::rightJoin($fromAlias, $join, $alias, $condition);
+				return $this;
 			} else {
 				throw new \InvalidArgumentException("Invalid join mode: $joinMode");
 			}
@@ -333,11 +333,11 @@ private function splitPredicatesByParts(array $predicates): array {
 		return $partitionPredicates;
 	}
 
-	public function where(...$predicates) {
+	public function where(...$predicates): self {
 		return $this->andWhere(...$predicates);
 	}
 
-	public function andWhere(...$where) {
+	public function andWhere(...$where): self {
 		if ($where) {
 			foreach ($this->splitPredicatesByParts($where) as $alias => $predicates) {
 				if (isset($this->splitQueries[$alias])) {
@@ -380,30 +380,35 @@ private function getPartitionForPredicate(string $predicate): ?PartitionSplit {
 		return null;
 	}
 
-	public function update($update = null, $alias = null) {
-		return parent::update($update, $alias);
+	public function update(string $update, ?string $alias = null): self {
+		parent::update($update, $alias);
+		return $this;
 	}
 
-	public function insert($insert = null) {
-		return parent::insert($insert);
+	public function insert(string $insert): self {
+		parent::insert($insert);
+		return $this;
 	}
 
-	public function delete($delete = null, $alias = null) {
-		return parent::delete($delete, $alias);
+	public function delete(string $delete, ?string $alias = null): self {
+		parent::delete($delete, $alias);
+		return $this;
 	}
 
-	public function setMaxResults($maxResults) {
-		if ($maxResults > 0) {
-			$this->limit = (int)$maxResults;
+	public function setMaxResults(?int $maxResults): self {
+		if ($maxResults !== null && $maxResults > 0) {
+			$this->limit = $maxResults;
 		}
-		return parent::setMaxResults($maxResults);
+		parent::setMaxResults($maxResults);
+		return $this;
 	}
 
-	public function setFirstResult($firstResult) {
+	public function setFirstResult(int $firstResult): self {
 		if ($firstResult > 0) {
-			$this->offset = (int)$firstResult;
+			$this->offset = $firstResult;
 		}
-		return parent::setFirstResult($firstResult);
+		parent::setFirstResult($firstResult);
+		return $this;
 	}
 
 	public function executeQuery(?IDBConnection $connection = null): IResult {
@@ -444,7 +449,7 @@ public function executeStatement(?IDBConnection $connection = null): int {
 		return parent::executeStatement($connection);
 	}
 
-	public function getSQL() {
+	public function getSQL(): string {
 		$this->applySelects();
 		return parent::getSQL();
 	}
diff --git a/lib/private/DB/QueryBuilder/QueryBuilder.php b/lib/private/DB/QueryBuilder/QueryBuilder.php
index 82fc6f84117c8..8e7307d5e4736 100644
--- a/lib/private/DB/QueryBuilder/QueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/QueryBuilder.php
@@ -20,78 +20,46 @@
 use OC\SystemConfig;
 use OCP\DB\IResult;
 use OCP\DB\QueryBuilder\ICompositeExpression;
+use OCP\DB\QueryBuilder\IExpressionBuilder;
+use OCP\DB\QueryBuilder\IFunctionBuilder;
 use OCP\DB\QueryBuilder\ILiteral;
 use OCP\DB\QueryBuilder\IParameter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\DB\QueryBuilder\IQueryFunction;
 use OCP\IDBConnection;
+use Override;
 use Psr\Log\LoggerInterface;
 
 class QueryBuilder implements IQueryBuilder {
-	/** @var ConnectionAdapter */
-	private $connection;
+	private \Doctrine\DBAL\Query\QueryBuilder $queryBuilder;
+	private QuoteHelper $helper;
 
-	/** @var SystemConfig */
-	private $systemConfig;
-
-	private LoggerInterface $logger;
-
-	/** @var \Doctrine\DBAL\Query\QueryBuilder */
-	private $queryBuilder;
-
-	/** @var QuoteHelper */
-	private $helper;
-
-	/** @var bool */
-	private $automaticTablePrefix = true;
+	private bool $automaticTablePrefix = true;
 	private bool $nonEmptyWhere = false;
 
-	/** @var string */
-	protected $lastInsertedTable;
+	protected ?string $lastInsertedTable = null;
+	/** @var string[] */
 	private array $selectedColumns = [];
 
 	/**
 	 * Initializes a new QueryBuilder.
-	 *
-	 * @param ConnectionAdapter $connection
-	 * @param SystemConfig $systemConfig
 	 */
-	public function __construct(ConnectionAdapter $connection, SystemConfig $systemConfig, LoggerInterface $logger) {
-		$this->connection = $connection;
-		$this->systemConfig = $systemConfig;
-		$this->logger = $logger;
+	public function __construct(
+		private readonly ConnectionAdapter $connection,
+		private readonly SystemConfig $systemConfig,
+		private readonly LoggerInterface $logger,
+	) {
 		$this->queryBuilder = new \Doctrine\DBAL\Query\QueryBuilder($this->connection->getInner());
 		$this->helper = new QuoteHelper();
 	}
 
-	/**
-	 * Enable/disable automatic prefixing of table names with the oc_ prefix
-	 *
-	 * @param bool $enabled If set to true table names will be prefixed with the
-	 *                      owncloud database prefix automatically.
-	 * @since 8.2.0
-	 */
-	public function automaticTablePrefix($enabled) {
-		$this->automaticTablePrefix = (bool)$enabled;
+	#[Override]
+	public function automaticTablePrefix(bool $enabled): void {
+		$this->automaticTablePrefix = $enabled;
 	}
 
-	/**
-	 * Gets an ExpressionBuilder used for object-oriented construction of query expressions.
-	 * This producer method is intended for convenient inline usage. Example:
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('users', 'u')
-	 *         ->where($qb->expr()->eq('u.id', 1));
-	 * </code>
-	 *
-	 * For more complex expression construction, consider storing the expression
-	 * builder object in a local variable.
-	 *
-	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
-	 */
-	public function expr() {
+	#[Override]
+	public function expr(): IExpressionBuilder {
 		return match($this->connection->getDatabaseProvider()) {
 			IDBConnection::PLATFORM_ORACLE => new OCIExpressionBuilder($this->connection, $this, $this->logger),
 			IDBConnection::PLATFORM_POSTGRES => new PgSqlExpressionBuilder($this->connection, $this, $this->logger),
@@ -101,23 +69,8 @@ public function expr() {
 		};
 	}
 
-	/**
-	 * Gets an FunctionBuilder used for object-oriented construction of query functions.
-	 * This producer method is intended for convenient inline usage. Example:
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('users', 'u')
-	 *         ->where($qb->fun()->md5('u.id'));
-	 * </code>
-	 *
-	 * For more complex function construction, consider storing the function
-	 * builder object in a local variable.
-	 *
-	 * @return \OCP\DB\QueryBuilder\IFunctionBuilder
-	 */
-	public function func() {
+	#[Override]
+	public function func(): IFunctionBuilder {
 		return match($this->connection->getDatabaseProvider()) {
 			IDBConnection::PLATFORM_ORACLE => new OCIFunctionBuilder($this->connection, $this, $this->helper),
 			IDBConnection::PLATFORM_POSTGRES => new PgSqlFunctionBuilder($this->connection, $this, $this->helper),
@@ -127,37 +80,23 @@ public function func() {
 		};
 	}
 
-	/**
-	 * Gets the type of the currently built query.
-	 *
-	 * @return integer
-	 */
-	public function getType() {
+	#[Override]
+	public function getType(): int {
 		return $this->queryBuilder->getType();
 	}
 
-	/**
-	 * Gets the associated DBAL Connection for this query builder.
-	 *
-	 * @return \OCP\IDBConnection
-	 */
-	public function getConnection() {
+	#[Override]
+	public function getConnection(): IDBConnection {
 		return $this->connection;
 	}
 
-	/**
-	 * Gets the state of this query builder instance.
-	 *
-	 * @return int Always returns 0 which is former `QueryBuilder::STATE_DIRTY`
-	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
-	 *    and we can not fix this in our wrapper.
-	 */
-	public function getState() {
+	#[Override]
+	public function getState(): int {
 		$this->logger->debug(IQueryBuilder::class . '::' . __FUNCTION__ . ' is deprecated and will be removed soon.', ['exception' => new \Exception('Deprecated call to ' . __METHOD__)]);
 		return $this->queryBuilder->getState();
 	}
 
-	private function prepareForExecute() {
+	private function prepareForExecute(): void {
 		if ($this->systemConfig->getValue('log_query', false)) {
 			try {
 				$params = [];
@@ -253,6 +192,7 @@ private function prepareForExecute() {
 		}
 	}
 
+	#[Override]
 	public function executeQuery(?IDBConnection $connection = null): IResult {
 		if ($this->getType() !== \Doctrine\DBAL\Query\QueryBuilder::SELECT) {
 			throw new \RuntimeException('Invalid query type, expected SELECT query');
@@ -270,6 +210,7 @@ public function executeQuery(?IDBConnection $connection = null): IResult {
 		);
 	}
 
+	#[Override]
 	public function executeStatement(?IDBConnection $connection = null): int {
 		if ($this->getType() === \Doctrine\DBAL\Query\QueryBuilder::SELECT) {
 			throw new \RuntimeException('Invalid query type, expected INSERT, DELETE or UPDATE statement');
@@ -287,181 +228,75 @@ public function executeStatement(?IDBConnection $connection = null): int {
 		);
 	}
 
-
-	/**
-	 * Gets the complete SQL string formed by the current specifications of this QueryBuilder.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('User', 'u')
-	 *     echo $qb->getSQL(); // SELECT u FROM User u
-	 * </code>
-	 *
-	 * @return string The SQL query string.
-	 */
-	public function getSQL() {
+	#[Override]
+	public function getSQL(): string {
 		return $this->queryBuilder->getSQL();
 	}
 
-	/**
-	 * Sets a query parameter for the query being constructed.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('users', 'u')
-	 *         ->where('u.id = :user_id')
-	 *         ->setParameter(':user_id', 1);
-	 * </code>
-	 *
-	 * @param string|integer $key The parameter position or name.
-	 * @param mixed $value The parameter value.
-	 * @param string|null|int $type One of the IQueryBuilder::PARAM_* constants.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function setParameter($key, $value, $type = null) {
+	#[Override]
+	public function setParameter(string|int $key, mixed $value, string|null|int $type = null): self {
 		$this->queryBuilder->setParameter($key, $value, $type);
 
 		return $this;
 	}
 
-	/**
-	 * Sets a collection of query parameters for the query being constructed.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('users', 'u')
-	 *         ->where('u.id = :user_id1 OR u.id = :user_id2')
-	 *         ->setParameters(array(
-	 *             ':user_id1' => 1,
-	 *             ':user_id2' => 2
-	 *         ));
-	 * </code>
-	 *
-	 * @param array $params The query parameters to set.
-	 * @param array $types The query parameters types to set.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function setParameters(array $params, array $types = []) {
+	#[Override]
+	public function setParameters(array $params, array $types = []): self {
 		$this->queryBuilder->setParameters($params, $types);
 
 		return $this;
 	}
 
-	/**
-	 * Gets all defined query parameters for the query being constructed indexed by parameter index or name.
-	 *
-	 * @return array The currently defined query parameters indexed by parameter index or name.
-	 */
-	public function getParameters() {
+	#[Override]
+	public function getParameters(): array {
 		return $this->queryBuilder->getParameters();
 	}
 
-	/**
-	 * Gets a (previously set) query parameter of the query being constructed.
-	 *
-	 * @param mixed $key The key (index or name) of the bound parameter.
-	 *
-	 * @return mixed The value of the bound parameter.
-	 */
-	public function getParameter($key) {
+	#[Override]
+	public function getParameter(int|string $key): mixed {
 		return $this->queryBuilder->getParameter($key);
 	}
 
-	/**
-	 * Gets all defined query parameter types for the query being constructed indexed by parameter index or name.
-	 *
-	 * @return array The currently defined query parameter types indexed by parameter index or name.
-	 */
-	public function getParameterTypes() {
+	#[Override]
+	public function getParameterTypes(): array {
 		return $this->queryBuilder->getParameterTypes();
 	}
 
-	/**
-	 * Gets a (previously set) query parameter type of the query being constructed.
-	 *
-	 * @param mixed $key The key (index or name) of the bound parameter type.
-	 *
-	 * @return mixed The value of the bound parameter type.
-	 */
-	public function getParameterType($key) {
+	#[Override]
+	public function getParameterType(int|string $key): mixed {
 		return $this->queryBuilder->getParameterType($key);
 	}
 
-	/**
-	 * Sets the position of the first result to retrieve (the "offset").
-	 *
-	 * @param int $firstResult The first result to return.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function setFirstResult($firstResult) {
-		$this->queryBuilder->setFirstResult((int)$firstResult);
+	#[Override]
+	public function setFirstResult(int $firstResult): self {
+		$this->queryBuilder->setFirstResult($firstResult);
 
 		return $this;
 	}
 
-	/**
-	 * Gets the position of the first result the query object was set to retrieve (the "offset").
-	 * Returns 0 if {@link setFirstResult} was not applied to this QueryBuilder.
-	 *
-	 * @return int The position of the first result.
-	 */
-	public function getFirstResult() {
+	#[Override]
+	public function getFirstResult(): int {
 		return $this->queryBuilder->getFirstResult();
 	}
 
-	/**
-	 * Sets the maximum number of results to retrieve (the "limit").
-	 *
-	 * NOTE: Setting max results to "0" will cause mixed behaviour. While most
-	 * of the databases will just return an empty result set, Oracle will return
-	 * all entries.
-	 *
-	 * @param int|null $maxResults The maximum number of results to retrieve.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function setMaxResults($maxResults) {
+	#[Override]
+	public function setMaxResults(?int $maxResults): self {
 		if ($maxResults === null) {
 			$this->queryBuilder->setMaxResults($maxResults);
 		} else {
-			$this->queryBuilder->setMaxResults((int)$maxResults);
+			$this->queryBuilder->setMaxResults($maxResults);
 		}
 
 		return $this;
 	}
 
-	/**
-	 * Gets the maximum number of results the query object was set to retrieve (the "limit").
-	 * Returns NULL if {@link setMaxResults} was not applied to this query builder.
-	 *
-	 * @return int|null The maximum number of results.
-	 */
-	public function getMaxResults() {
+	#[Override]
+	public function getMaxResults(): ?int {
 		return $this->queryBuilder->getMaxResults();
 	}
 
-	/**
-	 * Specifies an item that is to be returned in the query result.
-	 * Replaces any previously specified selections, if any.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.id', 'p.id')
-	 *         ->from('users', 'u')
-	 *         ->leftJoin('u', 'phonenumbers', 'p', 'u.id = p.user_id');
-	 * </code>
-	 *
-	 * @param mixed ...$selects The selection expressions.
-	 *
-	 * '@return $this This QueryBuilder instance.
-	 */
-	public function select(...$selects) {
+	#[Override]
+	public function select(...$selects): self {
 		if (count($selects) === 1 && is_array($selects[0])) {
 			$selects = $selects[0];
 		}
@@ -474,22 +309,8 @@ public function select(...$selects) {
 		return $this;
 	}
 
-	/**
-	 * Specifies an item that is to be returned with a different name in the query result.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->selectAlias('u.id', 'user_id')
-	 *         ->from('users', 'u')
-	 *         ->leftJoin('u', 'phonenumbers', 'p', 'u.id = p.user_id');
-	 * </code>
-	 *
-	 * @param mixed $select The selection expressions.
-	 * @param string $alias The column alias used in the constructed query.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function selectAlias($select, $alias) {
+	#[Override]
+	public function selectAlias(string|IParameter|IQueryFunction $select, string $alias): self {
 		$this->queryBuilder->addSelect(
 			$this->helper->quoteColumnName($select) . ' AS ' . $this->helper->quoteColumnName($alias)
 		);
@@ -498,20 +319,8 @@ public function selectAlias($select, $alias) {
 		return $this;
 	}
 
-	/**
-	 * Specifies an item that is to be returned uniquely in the query result.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->selectDistinct('type')
-	 *         ->from('users');
-	 * </code>
-	 *
-	 * @param mixed $select The selection expressions.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function selectDistinct($select) {
+	#[Override]
+	public function selectDistinct(string|array $select): self {
 		if (!is_array($select)) {
 			$select = [$select];
 		}
@@ -526,22 +335,8 @@ public function selectDistinct($select) {
 		return $this;
 	}
 
-	/**
-	 * Adds an item that is to be returned in the query result.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.id')
-	 *         ->addSelect('p.id')
-	 *         ->from('users', 'u')
-	 *         ->leftJoin('u', 'phonenumbers', 'u.id = p.user_id');
-	 * </code>
-	 *
-	 * @param mixed ...$selects The selection expression.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function addSelect(...$selects) {
+	#[Override]
+	public function addSelect(...$selects): self {
 		if (count($selects) === 1 && is_array($selects[0])) {
 			$selects = $selects[0];
 		}
@@ -570,28 +365,13 @@ private function addOutputColumns(array $columns): void {
 		}
 	}
 
+	#[Override]
 	public function getOutputColumns(): array {
 		return array_unique($this->selectedColumns);
 	}
 
-	/**
-	 * Turns the query being built into a bulk delete query that ranges over
-	 * a certain table.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->delete('users', 'u')
-	 *         ->where('u.id = :user_id');
-	 *         ->setParameter(':user_id', 1);
-	 * </code>
-	 *
-	 * @param string $delete The table whose rows are subject to the deletion.
-	 * @param string $alias The table alias used in the constructed query.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 * @since 30.0.0 Alias is deprecated and will no longer be used with the next Doctrine/DBAL update
-	 */
-	public function delete($delete = null, $alias = null) {
+	#[Override]
+	public function delete(string $delete, ?string $alias = null): self {
 		if ($alias !== null) {
 			$this->logger->debug('DELETE queries with alias are no longer supported and the provided alias is ignored', ['exception' => new \InvalidArgumentException('Table alias provided for DELETE query')]);
 		}
@@ -604,24 +384,8 @@ public function delete($delete = null, $alias = null) {
 		return $this;
 	}
 
-	/**
-	 * Turns the query being built into a bulk update query that ranges over
-	 * a certain table
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->update('users', 'u')
-	 *         ->set('u.password', md5('password'))
-	 *         ->where('u.id = ?');
-	 * </code>
-	 *
-	 * @param string $update The table whose rows are subject to the update.
-	 * @param string $alias The table alias used in the constructed query.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 * @since 30.0.0 Alias is deprecated and will no longer be used with the next Doctrine/DBAL update
-	 */
-	public function update($update = null, $alias = null) {
+	#[Override]
+	public function update(string $update, ?string $alias = null): self {
 		if ($alias !== null) {
 			$this->logger->debug('UPDATE queries with alias are no longer supported and the provided alias is ignored', ['exception' => new \InvalidArgumentException('Table alias provided for UPDATE query')]);
 		}
@@ -634,26 +398,8 @@ public function update($update = null, $alias = null) {
 		return $this;
 	}
 
-	/**
-	 * Turns the query being built into an insert query that inserts into
-	 * a certain table
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->insert('users')
-	 *         ->values(
-	 *             array(
-	 *                 'name' => '?',
-	 *                 'password' => '?'
-	 *             )
-	 *         );
-	 * </code>
-	 *
-	 * @param string $insert The table into which the rows should be inserted.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function insert($insert = null) {
+	#[Override]
+	public function insert(string $insert): self {
 		$this->queryBuilder->insert(
 			$this->getTableName($insert)
 		);
@@ -663,48 +409,18 @@ public function insert($insert = null) {
 		return $this;
 	}
 
-	/**
-	 * Creates and adds a query root corresponding to the table identified by the
-	 * given alias, forming a cartesian product with any existing query roots.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.id')
-	 *         ->from('users', 'u')
-	 * </code>
-	 *
-	 * @param string|IQueryFunction $from The table.
-	 * @param string|null $alias The alias of the table.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function from($from, $alias = null) {
+	#[Override]
+	public function from(string|IQueryFunction $from, ?string $alias = null): self {
 		$this->queryBuilder->from(
 			$this->getTableName($from),
-			$this->quoteAlias($alias)
+			$alias ? $this->quoteAlias($alias) : null,
 		);
 
 		return $this;
 	}
 
-	/**
-	 * Creates and adds a join to the query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->join('u', 'phonenumbers', 'p', 'p.is_primary = 1');
-	 * </code>
-	 *
-	 * @param string $fromAlias The alias that points to a from clause.
-	 * @param string $join The table name to join.
-	 * @param string $alias The alias of the join table.
-	 * @param string|ICompositeExpression|null $condition The condition for the join.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function join($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function join(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self {
 		$this->queryBuilder->join(
 			$this->quoteAlias($fromAlias),
 			$this->getTableName($join),
@@ -715,24 +431,8 @@ public function join($fromAlias, $join, $alias, $condition = null) {
 		return $this;
 	}
 
-	/**
-	 * Creates and adds a join to the query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->innerJoin('u', 'phonenumbers', 'p', 'p.is_primary = 1');
-	 * </code>
-	 *
-	 * @param string $fromAlias The alias that points to a from clause.
-	 * @param string $join The table name to join.
-	 * @param string $alias The alias of the join table.
-	 * @param string|ICompositeExpression|null $condition The condition for the join.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function innerJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function innerJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self {
 		$this->queryBuilder->innerJoin(
 			$this->quoteAlias($fromAlias),
 			$this->getTableName($join),
@@ -743,24 +443,8 @@ public function innerJoin($fromAlias, $join, $alias, $condition = null) {
 		return $this;
 	}
 
-	/**
-	 * Creates and adds a left join to the query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->leftJoin('u', 'phonenumbers', 'p', 'p.is_primary = 1');
-	 * </code>
-	 *
-	 * @param string $fromAlias The alias that points to a from clause.
-	 * @param string|IQueryFunction $join The table name or sub-query to join.
-	 * @param string $alias The alias of the join table.
-	 * @param string|ICompositeExpression|null $condition The condition for the join.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function leftJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function leftJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self {
 		$this->queryBuilder->leftJoin(
 			$this->quoteAlias($fromAlias),
 			$this->getTableName($join),
@@ -771,24 +455,8 @@ public function leftJoin($fromAlias, $join, $alias, $condition = null) {
 		return $this;
 	}
 
-	/**
-	 * Creates and adds a right join to the query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->rightJoin('u', 'phonenumbers', 'p', 'p.is_primary = 1');
-	 * </code>
-	 *
-	 * @param string $fromAlias The alias that points to a from clause.
-	 * @param string $join The table name to join.
-	 * @param string $alias The alias of the join table.
-	 * @param string|ICompositeExpression|null $condition The condition for the join.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function rightJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function rightJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self {
 		$this->queryBuilder->rightJoin(
 			$this->quoteAlias($fromAlias),
 			$this->getTableName($join),
@@ -799,22 +467,8 @@ public function rightJoin($fromAlias, $join, $alias, $condition = null) {
 		return $this;
 	}
 
-	/**
-	 * Sets a new value for a column in a bulk update query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->update('users', 'u')
-	 *         ->set('u.password', md5('password'))
-	 *         ->where('u.id = ?');
-	 * </code>
-	 *
-	 * @param string $key The column to set.
-	 * @param ILiteral|IParameter|IQueryFunction|string $value The value, expression, placeholder, etc.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function set($key, $value) {
+	#[Override]
+	public function set(string $key, ILiteral|IParameter|IQueryFunction|string $value): self {
 		$this->queryBuilder->set(
 			$this->helper->quoteColumnName($key),
 			$this->helper->quoteColumnName($value)
@@ -823,34 +477,8 @@ public function set($key, $value) {
 		return $this;
 	}
 
-	/**
-	 * Specifies one or more restrictions to the query result.
-	 * Replaces any previously specified restrictions, if any.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->where('u.id = ?');
-	 *
-	 *     // You can optionally programmatically build and/or expressions
-	 *     $qb = $conn->getQueryBuilder();
-	 *
-	 *     $or = $qb->expr()->orx(
-	 *         $qb->expr()->eq('u.id', 1),
-	 *         $qb->expr()->eq('u.id', 2),
-	 *     );
-	 *
-	 *     $qb->update('users', 'u')
-	 *         ->set('u.password', md5('password'))
-	 *         ->where($or);
-	 * </code>
-	 *
-	 * @param mixed ...$predicates The restriction predicates.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function where(...$predicates) {
+	#[Override]
+	public function where(...$predicates): self {
 		if ($this->nonEmptyWhere && $this->systemConfig->getValue('debug', false)) {
 			// Only logging a warning, not throwing for now.
 			$e = new QueryException('Using where() on non-empty WHERE part, please verify it is intentional to not call andWhere() or orWhere() instead. Otherwise consider creating a new query builder object or call resetQueryPart(\'where\') first.');
@@ -867,25 +495,8 @@ public function where(...$predicates) {
 		return $this;
 	}
 
-	/**
-	 * Adds one or more restrictions to the query results, forming a logical
-	 * conjunction with any previously specified restrictions.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u')
-	 *         ->from('users', 'u')
-	 *         ->where('u.username LIKE ?')
-	 *         ->andWhere('u.is_active = 1');
-	 * </code>
-	 *
-	 * @param mixed ...$where The query restrictions.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 *
-	 * @see where()
-	 */
-	public function andWhere(...$where) {
+	#[Override]
+	public function andWhere(...$where): self {
 		$this->nonEmptyWhere = true;
 		call_user_func_array(
 			[$this->queryBuilder, 'andWhere'],
@@ -895,25 +506,8 @@ public function andWhere(...$where) {
 		return $this;
 	}
 
-	/**
-	 * Adds one or more restrictions to the query results, forming a logical
-	 * disjunction with any previously specified restrictions.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->where('u.id = 1')
-	 *         ->orWhere('u.id = 2');
-	 * </code>
-	 *
-	 * @param mixed ...$where The WHERE statement.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 *
-	 * @see where()
-	 */
-	public function orWhere(...$where) {
+	#[Override]
+	public function orWhere(...$where): self {
 		$this->nonEmptyWhere = true;
 		call_user_func_array(
 			[$this->queryBuilder, 'orWhere'],
@@ -923,22 +517,8 @@ public function orWhere(...$where) {
 		return $this;
 	}
 
-	/**
-	 * Specifies a grouping over the results of the query.
-	 * Replaces any previously specified groupings, if any.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->groupBy('u.id');
-	 * </code>
-	 *
-	 * @param mixed ...$groupBys The grouping expression.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function groupBy(...$groupBys) {
+	#[Override]
+	public function groupBy(...$groupBys): self {
 		if (count($groupBys) === 1 && is_array($groupBys[0])) {
 			$groupBys = $groupBys[0];
 		}
@@ -951,22 +531,8 @@ public function groupBy(...$groupBys) {
 		return $this;
 	}
 
-	/**
-	 * Adds a grouping expression to the query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->select('u.name')
-	 *         ->from('users', 'u')
-	 *         ->groupBy('u.lastLogin');
-	 *         ->addGroupBy('u.createdAt')
-	 * </code>
-	 *
-	 * @param mixed ...$groupBy The grouping expression.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function addGroupBy(...$groupBy) {
+	#[Override]
+	public function addGroupBy(...$groupBy): self {
 		call_user_func_array(
 			[$this->queryBuilder, 'addGroupBy'],
 			$this->helper->quoteColumnNames($groupBy)
@@ -975,26 +541,8 @@ public function addGroupBy(...$groupBy) {
 		return $this;
 	}
 
-	/**
-	 * Sets a value for a column in an insert query.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->insert('users')
-	 *         ->values(
-	 *             array(
-	 *                 'name' => '?'
-	 *             )
-	 *         )
-	 *         ->setValue('password', '?');
-	 * </code>
-	 *
-	 * @param string $column The column into which the value should be inserted.
-	 * @param IParameter|string $value The value that should be inserted into the column.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function setValue($column, $value) {
+	#[Override]
+	public function setValue(string $column, IParameter|IQueryFunction|string $value): self {
 		$this->queryBuilder->setValue(
 			$this->helper->quoteColumnName($column),
 			(string)$value
@@ -1003,26 +551,8 @@ public function setValue($column, $value) {
 		return $this;
 	}
 
-	/**
-	 * Specifies values for an insert query indexed by column names.
-	 * Replaces any previous values, if any.
-	 *
-	 * <code>
-	 *     $qb = $conn->getQueryBuilder()
-	 *         ->insert('users')
-	 *         ->values(
-	 *             array(
-	 *                 'name' => '?',
-	 *                 'password' => '?'
-	 *             )
-	 *         );
-	 * </code>
-	 *
-	 * @param array $values The values to specify for the insert query indexed by column names.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function values(array $values) {
+	#[Override]
+	public function values(array $values): self {
 		$quotedValues = [];
 		foreach ($values as $key => $value) {
 			$quotedValues[$this->helper->quoteColumnName($key)] = $value;
@@ -1033,15 +563,8 @@ public function values(array $values) {
 		return $this;
 	}
 
-	/**
-	 * Specifies a restriction over the groups of the query.
-	 * Replaces any previous having restrictions, if any.
-	 *
-	 * @param mixed ...$having The restriction over the groups.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function having(...$having) {
+	#[Override]
+	public function having(...$having): self {
 		call_user_func_array(
 			[$this->queryBuilder, 'having'],
 			$having
@@ -1050,15 +573,8 @@ public function having(...$having) {
 		return $this;
 	}
 
-	/**
-	 * Adds a restriction over the groups of the query, forming a logical
-	 * conjunction with any existing having restrictions.
-	 *
-	 * @param mixed ...$having The restriction to append.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function andHaving(...$having) {
+	#[Override]
+	public function andHaving(...$having): self {
 		call_user_func_array(
 			[$this->queryBuilder, 'andHaving'],
 			$having
@@ -1067,15 +583,8 @@ public function andHaving(...$having) {
 		return $this;
 	}
 
-	/**
-	 * Adds a restriction over the groups of the query, forming a logical
-	 * disjunction with any existing having restrictions.
-	 *
-	 * @param mixed ...$having The restriction to add.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function orHaving(...$having) {
+	#[Override]
+	public function orHaving(...$having): self {
 		call_user_func_array(
 			[$this->queryBuilder, 'orHaving'],
 			$having
@@ -1084,17 +593,9 @@ public function orHaving(...$having) {
 		return $this;
 	}
 
-	/**
-	 * Specifies an ordering for the query results.
-	 * Replaces any previously specified orderings, if any.
-	 *
-	 * @param string|IQueryFunction|ILiteral|IParameter $sort The ordering expression.
-	 * @param string $order The ordering direction.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function orderBy($sort, $order = null) {
-		if ($order !== null && !in_array(strtoupper((string)$order), ['ASC', 'DESC'], true)) {
+	#[Override]
+	public function orderBy(string|ILiteral|IParameter|IQueryFunction $sort, ?string $order = null): self {
+		if ($order !== null && !in_array(strtoupper($order), ['ASC', 'DESC'], true)) {
 			$order = null;
 		}
 
@@ -1106,16 +607,9 @@ public function orderBy($sort, $order = null) {
 		return $this;
 	}
 
-	/**
-	 * Adds an ordering to the query results.
-	 *
-	 * @param string|ILiteral|IParameter|IQueryFunction $sort The ordering expression.
-	 * @param string $order The ordering direction.
-	 *
-	 * @return $this This QueryBuilder instance.
-	 */
-	public function addOrderBy($sort, $order = null) {
-		if ($order !== null && !in_array(strtoupper((string)$order), ['ASC', 'DESC'], true)) {
+	#[Override]
+	public function addOrderBy(string|ILiteral|IParameter|IQueryFunction $sort, ?string $order = null): self {
+		if ($order !== null && !in_array(strtoupper($order), ['ASC', 'DESC'], true)) {
 			$order = null;
 		}
 
@@ -1127,177 +621,57 @@ public function addOrderBy($sort, $order = null) {
 		return $this;
 	}
 
-	/**
-	 * Gets a query part by its name.
-	 *
-	 * @param string $queryPartName
-	 *
-	 * @return mixed
-	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
-	 *   and we can not fix this in our wrapper. Please track the details you need, outside the object.
-	 */
-	public function getQueryPart($queryPartName) {
+	#[Override]
+	public function getQueryPart(string $queryPartName): mixed {
 		$this->logger->debug(IQueryBuilder::class . '::' . __FUNCTION__ . ' is deprecated and will be removed soon.', ['exception' => new \Exception('Deprecated call to ' . __METHOD__)]);
 		return $this->queryBuilder->getQueryPart($queryPartName);
 	}
 
-	/**
-	 * Gets all query parts.
-	 *
-	 * @return array
-	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
-	 *   and we can not fix this in our wrapper. Please track the details you need, outside the object.
-	 */
-	public function getQueryParts() {
+	#[Override]
+	public function getQueryParts(): array {
 		$this->logger->debug(IQueryBuilder::class . '::' . __FUNCTION__ . ' is deprecated and will be removed soon.', ['exception' => new \Exception('Deprecated call to ' . __METHOD__)]);
 		return $this->queryBuilder->getQueryParts();
 	}
 
-	/**
-	 * Resets SQL parts.
-	 *
-	 * @param array|null $queryPartNames
-	 *
-	 * @return $this This QueryBuilder instance.
-	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
-	 *  and we can not fix this in our wrapper. Please create a new IQueryBuilder instead.
-	 */
-	public function resetQueryParts($queryPartNames = null) {
+	#[Override]
+	public function resetQueryParts(?array $queryPartNames = null): self {
 		$this->logger->debug(IQueryBuilder::class . '::' . __FUNCTION__ . ' is deprecated and will be removed soon.', ['exception' => new \Exception('Deprecated call to ' . __METHOD__)]);
 		$this->queryBuilder->resetQueryParts($queryPartNames);
 
 		return $this;
 	}
 
-	/**
-	 * Resets a single SQL part.
-	 *
-	 * @param string $queryPartName
-	 *
-	 * @return $this This QueryBuilder instance.
-	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
-	 *  and we can not fix this in our wrapper. Please create a new IQueryBuilder instead.
-	 */
-	public function resetQueryPart($queryPartName) {
+	#[Override]
+	public function resetQueryPart(string $queryPartName): self {
 		$this->logger->debug(IQueryBuilder::class . '::' . __FUNCTION__ . ' is deprecated and will be removed soon.', ['exception' => new \Exception('Deprecated call to ' . __METHOD__)]);
 		$this->queryBuilder->resetQueryPart($queryPartName);
 
 		return $this;
 	}
 
-	/**
-	 * Creates a new named parameter and bind the value $value to it.
-	 *
-	 * This method provides a shortcut for PDOStatement::bindValue
-	 * when using prepared statements.
-	 *
-	 * The parameter $value specifies the value that you want to bind. If
-	 * $placeholder is not provided bindValue() will automatically create a
-	 * placeholder for you. An automatic placeholder will be of the name
-	 * ':dcValue1', ':dcValue2' etc.
-	 *
-	 * For more information see {@link https://www.php.net/pdostatement-bindparam}
-	 *
-	 * Example:
-	 * <code>
-	 * $value = 2;
-	 * $q->eq( 'id', $q->bindValue( $value ) );
-	 * $stmt = $q->executeQuery(); // executed with 'id = 2'
-	 * </code>
-	 *
-	 * @license New BSD License
-	 * @link http://www.zetacomponents.org
-	 *
-	 * @param mixed $value
-	 * @param IQueryBuilder::PARAM_* $type
-	 * @param string $placeHolder The name to bind with. The string must start with a colon ':'.
-	 *
-	 * @return IParameter the placeholder name used.
-	 */
-	public function createNamedParameter($value, $type = IQueryBuilder::PARAM_STR, $placeHolder = null) {
+	#[Override]
+	public function createNamedParameter(mixed $value, mixed $type = IQueryBuilder::PARAM_STR, ?string $placeHolder = null): IParameter {
 		return new Parameter($this->queryBuilder->createNamedParameter($value, $type, $placeHolder));
 	}
 
-	/**
-	 * Creates a new positional parameter and bind the given value to it.
-	 *
-	 * Attention: If you are using positional parameters with the query builder you have
-	 * to be very careful to bind all parameters in the order they appear in the SQL
-	 * statement , otherwise they get bound in the wrong order which can lead to serious
-	 * bugs in your code.
-	 *
-	 * Example:
-	 * <code>
-	 *  $qb = $conn->getQueryBuilder();
-	 *  $qb->select('u.*')
-	 *     ->from('users', 'u')
-	 *     ->where('u.username = ' . $qb->createPositionalParameter('Foo', IQueryBuilder::PARAM_STR))
-	 *     ->orWhere('u.username = ' . $qb->createPositionalParameter('Bar', IQueryBuilder::PARAM_STR))
-	 * </code>
-	 *
-	 * @param mixed $value
-	 * @param IQueryBuilder::PARAM_* $type
-	 *
-	 * @return IParameter
-	 */
-	public function createPositionalParameter($value, $type = IQueryBuilder::PARAM_STR) {
+	#[Override]
+	public function createPositionalParameter(mixed $value, mixed $type = IQueryBuilder::PARAM_STR): IParameter {
 		return new Parameter($this->queryBuilder->createPositionalParameter($value, $type));
 	}
 
-	/**
-	 * Creates a new parameter
-	 *
-	 * Example:
-	 * <code>
-	 *  $qb = $conn->getQueryBuilder();
-	 *  $qb->select('u.*')
-	 *     ->from('users', 'u')
-	 *     ->where('u.username = ' . $qb->createParameter('name'))
-	 *     ->setParameter('name', 'Bar', IQueryBuilder::PARAM_STR))
-	 * </code>
-	 *
-	 * @param string $name
-	 *
-	 * @return IParameter
-	 */
-	public function createParameter($name) {
+	#[Override]
+	public function createParameter(string $name): IParameter {
 		return new Parameter(':' . $name);
 	}
 
-	/**
-	 * Creates a new function
-	 *
-	 * Attention: Column names inside the call have to be quoted before hand
-	 *
-	 * Example:
-	 * <code>
-	 *  $qb = $conn->getQueryBuilder();
-	 *  $qb->select($qb->createFunction('COUNT(*)'))
-	 *     ->from('users', 'u')
-	 *  echo $qb->getSQL(); // SELECT COUNT(*) FROM `users` u
-	 * </code>
-	 * <code>
-	 *  $qb = $conn->getQueryBuilder();
-	 *  $qb->select($qb->createFunction('COUNT(`column`)'))
-	 *     ->from('users', 'u')
-	 *  echo $qb->getSQL(); // SELECT COUNT(`column`) FROM `users` u
-	 * </code>
-	 *
-	 * @param string $call
-	 *
-	 * @return IQueryFunction
-	 */
-	public function createFunction($call) {
+	#[Override]
+	public function createFunction(string $call): IQueryFunction {
 		return new QueryFunction($call);
 	}
 
-	/**
-	 * Used to get the id of the last inserted element
-	 * @return int
-	 * @throws \BadMethodCallException When being called before an insert query has been run.
-	 */
+	#[Override]
 	public function getLastInsertId(): int {
-		if ($this->getType() === \Doctrine\DBAL\Query\QueryBuilder::INSERT && $this->lastInsertedTable) {
+		if ($this->getType() === \Doctrine\DBAL\Query\QueryBuilder::INSERT && $this->lastInsertedTable !== null) {
 			// lastInsertId() needs the prefix but no quotes
 			$table = $this->prefixTableName($this->lastInsertedTable);
 			return $this->connection->lastInsertId($table);
@@ -1306,13 +680,8 @@ public function getLastInsertId(): int {
 		throw new \BadMethodCallException('Invalid call to getLastInsertId without using insert() before.');
 	}
 
-	/**
-	 * Returns the table name quoted and with database prefix as needed by the implementation
-	 *
-	 * @param string|IQueryFunction $table
-	 * @return string
-	 */
-	public function getTableName($table) {
+	#[Override]
+	public function getTableName(string|IQueryFunction $table): string {
 		if ($table instanceof IQueryFunction) {
 			return (string)$table;
 		}
@@ -1321,14 +690,7 @@ public function getTableName($table) {
 		return $this->helper->quoteColumnName($table);
 	}
 
-	/**
-	 * Returns the table name with database prefix as needed by the implementation
-	 *
-	 * Was protected until version 30.
-	 *
-	 * @param string $table
-	 * @return string
-	 */
+	#[Override]
 	public function prefixTableName(string $table): string {
 		if ($this->automaticTablePrefix === false || str_starts_with($table, '*PREFIX*')) {
 			return $table;
@@ -1337,14 +699,8 @@ public function prefixTableName(string $table): string {
 		return '*PREFIX*' . $table;
 	}
 
-	/**
-	 * Returns the column name quoted and with table alias prefix as needed by the implementation
-	 *
-	 * @param string $column
-	 * @param string $tableAlias
-	 * @return string
-	 */
-	public function getColumnName($column, $tableAlias = '') {
+	#[Override]
+	public function getColumnName(string $column, string $tableAlias = ''): string {
 		if ($tableAlias !== '') {
 			$tableAlias .= '.';
 		}
@@ -1352,14 +708,8 @@ public function getColumnName($column, $tableAlias = '') {
 		return $this->helper->quoteColumnName($tableAlias . $column);
 	}
 
-	/**
-	 * Returns the column name quoted and with table alias prefix as needed by the implementation
-	 *
-	 * @param string $alias
-	 * @return string
-	 */
-	public function quoteAlias($alias) {
-		if ($alias === '' || $alias === null) {
+	public function quoteAlias(string $alias): string {
+		if ($alias === '') {
 			return $alias;
 		}
 
@@ -1370,10 +720,12 @@ public function escapeLikeParameter(string $parameter): string {
 		return $this->connection->escapeLikeParameter($parameter);
 	}
 
+	#[Override]
 	public function hintShardKey(string $column, mixed $value, bool $overwrite = false): self {
 		return $this;
 	}
 
+	#[Override]
 	public function runAcrossAllShards(): self {
 		// noop
 		return $this;
diff --git a/lib/private/DB/QueryBuilder/QuoteHelper.php b/lib/private/DB/QueryBuilder/QuoteHelper.php
index 7ce4b359638d4..4ebbc53ed4e5c 100644
--- a/lib/private/DB/QueryBuilder/QuoteHelper.php
+++ b/lib/private/DB/QueryBuilder/QuoteHelper.php
@@ -12,11 +12,7 @@
 use OCP\DB\QueryBuilder\IQueryFunction;
 
 class QuoteHelper {
-	/**
-	 * @param array|string|ILiteral|IParameter|IQueryFunction $strings string, Literal or Parameter
-	 * @return array|string
-	 */
-	public function quoteColumnNames($strings) {
+	public function quoteColumnNames(array|string|ILiteral|IParameter|IQueryFunction $strings): array|string {
 		if (!is_array($strings)) {
 			return $this->quoteColumnName($strings);
 		}
@@ -29,23 +25,15 @@ public function quoteColumnNames($strings) {
 		return $return;
 	}
 
-	/**
-	 * @param string|ILiteral|IParameter|IQueryFunction $string string, Literal or Parameter
-	 * @return string
-	 */
-	public function quoteColumnName($string) {
+	public function quoteColumnName(string|ILiteral|IParameter|IQueryFunction $string): string {
 		if ($string instanceof IParameter || $string instanceof ILiteral || $string instanceof IQueryFunction) {
 			return (string)$string;
 		}
 
-		if ($string === null || $string === 'null' || $string === '*') {
+		if ($string === 'null' || $string === '*') {
 			return $string;
 		}
 
-		if (!is_string($string)) {
-			throw new \InvalidArgumentException('Only strings, Literals and Parameters are allowed');
-		}
-
 		$string = str_replace(' AS ', ' as ', $string);
 		if (substr_count($string, ' as ')) {
 			return implode(' as ', array_map([$this, 'quoteColumnName'], explode(' as ', $string, 2)));
diff --git a/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php b/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
index 2694a116af43f..36443d9bbab4e 100644
--- a/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
+++ b/lib/private/DB/QueryBuilder/Sharded/ShardedQueryBuilder.php
@@ -12,8 +12,11 @@
 use OC\DB\QueryBuilder\ExtendedQueryBuilder;
 use OC\DB\QueryBuilder\Parameter;
 use OCP\DB\IResult;
+use OCP\DB\QueryBuilder\IParameter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\DB\QueryBuilder\IQueryFunction;
 use OCP\IDBConnection;
+use Override;
 
 /**
  * A special query builder that automatically distributes queries over multiple database shards.
@@ -83,11 +86,13 @@ private function getKeyValue($value): array {
 		}
 	}
 
-	public function where(...$predicates) {
+	#[Override]
+	public function where(...$predicates): self {
 		return $this->andWhere(...$predicates);
 	}
 
-	public function andWhere(...$where) {
+	#[Override]
+	public function andWhere(...$where): self {
 		if ($where) {
 			foreach ($where as $predicate) {
 				$this->tryLoadShardKey($predicate);
@@ -158,14 +163,18 @@ private function tryExtractShardKeys($predicate, string $column): array {
 		return [];
 	}
 
-	public function set($key, $value) {
+	#[Override]
+	public function set($key, $value): self {
 		if ($this->shardDefinition && $key === $this->shardDefinition->shardKey) {
+			// TODO dead code?
 			$updateShardKey = $value;
 		}
-		return parent::set($key, $value);
+		parent::set($key, $value);
+		return $this;
 	}
 
-	public function setValue($column, $value) {
+	#[Override]
+	public function setValue(string $column, IParameter|IQueryFunction|string $value): self {
 		if ($this->shardDefinition) {
 			if ($this->shardDefinition->isKey($column)) {
 				$this->primaryKeys[] = $value;
@@ -174,10 +183,12 @@ public function setValue($column, $value) {
 				$this->shardKeys[] = $value;
 			}
 		}
-		return parent::setValue($column, $value);
+		parent::setValue($column, $value);
+		return $this;
 	}
 
-	public function values(array $values) {
+	#[Override]
+	public function values(array $values): self {
 		foreach ($values as $column => $value) {
 			$this->setValue($column, $value);
 		}
@@ -193,33 +204,35 @@ private function actOnTable(string $table): void {
 		}
 	}
 
-	public function from($from, $alias = null) {
-		if (is_string($from) && $from) {
+	#[Override]
+	public function from(string|IQueryFunction $from, ?string $alias = null): self {
+		if (is_string($from)) {
 			$this->actOnTable($from);
 		}
-		return parent::from($from, $alias);
+		parent::from($from, $alias);
+		return $this;
 	}
 
-	public function update($update = null, $alias = null) {
-		if (is_string($update) && $update) {
-			$this->actOnTable($update);
-		}
-		return parent::update($update, $alias);
+	#[Override]
+	public function update(string $update, ?string $alias = null): self {
+		$this->actOnTable($update);
+		parent::update($update, $alias);
+		return $this;
 	}
 
-	public function insert($insert = null) {
-		if (is_string($insert) && $insert) {
-			$this->insertTable = $insert;
-			$this->actOnTable($insert);
-		}
-		return parent::insert($insert);
+	#[Override]
+	public function insert(string $insert): self {
+		$this->insertTable = $insert;
+		$this->actOnTable($insert);
+		parent::insert($insert);
+		return $this;
 	}
 
-	public function delete($delete = null, $alias = null) {
-		if (is_string($delete) && $delete) {
-			$this->actOnTable($delete);
-		}
-		return parent::delete($delete, $alias);
+	#[Override]
+	public function delete(string $delete, ?string $alias = null): self {
+		$this->actOnTable($delete);
+		parent::delete($delete, $alias);
+		return $this;
 	}
 
 	private function checkJoin(string $table): void {
@@ -235,67 +248,82 @@ private function checkJoin(string $table): void {
 		}
 	}
 
-	public function innerJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function innerJoin($fromAlias, $join, $alias, $condition = null): self {
 		if (is_string($join)) {
 			$this->checkJoin($join);
 		}
-		return parent::innerJoin($fromAlias, $join, $alias, $condition);
+		parent::innerJoin($fromAlias, $join, $alias, $condition);
+		return $this;
 	}
 
-	public function leftJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function leftJoin($fromAlias, $join, $alias, $condition = null): self {
 		if (is_string($join)) {
 			$this->checkJoin($join);
 		}
-		return parent::leftJoin($fromAlias, $join, $alias, $condition);
+		parent::leftJoin($fromAlias, $join, $alias, $condition);
+		return $this;
 	}
 
-	public function rightJoin($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function rightJoin($fromAlias, $join, $alias, $condition = null): self {
 		if ($this->shardDefinition) {
 			throw new InvalidShardedQueryException("Sharded query on {$this->shardDefinition->table} isn't allowed to right join");
 		}
-		return parent::rightJoin($fromAlias, $join, $alias, $condition);
+		parent::rightJoin($fromAlias, $join, $alias, $condition);
+		return $this;
 	}
 
-	public function join($fromAlias, $join, $alias, $condition = null) {
+	#[Override]
+	public function join($fromAlias, $join, $alias, $condition = null): self {
 		return $this->innerJoin($fromAlias, $join, $alias, $condition);
 	}
 
-	public function setMaxResults($maxResults) {
-		if ($maxResults > 0) {
-			$this->limit = (int)$maxResults;
+	#[Override]
+	public function setMaxResults(?int $maxResults): self {
+		if ($maxResults !== null && $maxResults > 0) {
+			$this->limit = $maxResults;
 		}
-		return parent::setMaxResults($maxResults);
+		parent::setMaxResults($maxResults);
+		return $this;
 	}
 
-	public function setFirstResult($firstResult) {
+	#[Override]
+	public function setFirstResult(int $firstResult): self {
 		if ($firstResult > 0) {
-			$this->offset = (int)$firstResult;
+			$this->offset = $firstResult;
 		}
 		if ($this->shardDefinition && count($this->shardDefinition->shards) > 1) {
 			// we have to emulate offset
 			return $this;
 		} else {
-			return parent::setFirstResult($firstResult);
+			parent::setFirstResult($firstResult);
+			return $this;
 		}
 	}
 
-	public function addOrderBy($sort, $order = null) {
+	#[Override]
+	public function addOrderBy($sort, $order = null): self {
 		if ($order !== null && !in_array(strtoupper((string)$order), ['ASC', 'DESC'], true)) {
 			$order = null;
 		}
 
 		$this->registerOrder((string)$sort, (string)($order ?? 'ASC'));
-		return parent::addOrderBy($sort, $order);
+		parent::addOrderBy($sort, $order);
+		return $this;
 	}
 
-	public function orderBy($sort, $order = null) {
+	#[Override]
+	public function orderBy($sort, $order = null): self {
 		if ($order !== null && !in_array(strtoupper((string)$order), ['ASC', 'DESC'], true)) {
 			$order = null;
 		}
 
 		$this->sortList = [];
 		$this->registerOrder((string)$sort, (string)($order ?? 'ASC'));
-		return parent::orderBy($sort, $order);
+		parent::orderBy($sort, $order);
+		return $this;
 	}
 
 	private function registerOrder(string $column, string $order): void {
@@ -308,6 +336,7 @@ private function registerOrder(string $column, string $order): void {
 		];
 	}
 
+	#[Override]
 	public function hintShardKey(string $column, mixed $value, bool $overwrite = false): self {
 		if ($overwrite) {
 			$this->primaryKeys = [];
@@ -322,6 +351,7 @@ public function hintShardKey(string $column, mixed $value, bool $overwrite = fal
 		return $this;
 	}
 
+	#[Override]
 	public function runAcrossAllShards(): self {
 		$this->allShards = true;
 		return $this;
@@ -364,6 +394,7 @@ public function validate(): void {
 		}
 	}
 
+	#[Override]
 	public function executeQuery(?IDBConnection $connection = null): IResult {
 		$this->validate();
 		if ($this->shardDefinition) {
@@ -373,6 +404,7 @@ public function executeQuery(?IDBConnection $connection = null): IResult {
 		return parent::executeQuery($connection);
 	}
 
+	#[Override]
 	public function executeStatement(?IDBConnection $connection = null): int {
 		$this->validate();
 		if ($this->shardDefinition) {
@@ -403,6 +435,7 @@ public function executeStatement(?IDBConnection $connection = null): int {
 		return parent::executeStatement($connection);
 	}
 
+	#[Override]
 	public function getLastInsertId(): int {
 		if ($this->lastInsertId) {
 			return $this->lastInsertId;
@@ -414,6 +447,4 @@ public function getLastInsertId(): int {
 			return parent::getLastInsertId();
 		}
 	}
-
-
 }
diff --git a/lib/private/Files/Cache/CacheQueryBuilder.php b/lib/private/Files/Cache/CacheQueryBuilder.php
index 5492452273bba..03474261048cc 100644
--- a/lib/private/Files/Cache/CacheQueryBuilder.php
+++ b/lib/private/Files/Cache/CacheQueryBuilder.php
@@ -45,7 +45,7 @@ public function selectTagUsage(): self {
 		return $this;
 	}
 
-	public function selectFileCache(?string $alias = null, bool $joinExtendedCache = true) {
+	public function selectFileCache(?string $alias = null, bool $joinExtendedCache = true): self {
 		$name = $alias ?: 'filecache';
 		$this->select("$name.fileid", 'storage', 'path', 'path_hash', "$name.parent", "$name.name", 'mimetype', 'mimepart', 'size', 'mtime',
 			'storage_mtime', 'encrypted', "$name.etag", "$name.permissions", 'checksum', 'unencrypted_size')
@@ -61,13 +61,13 @@ public function selectFileCache(?string $alias = null, bool $joinExtendedCache =
 		return $this;
 	}
 
-	public function whereStorageId(int $storageId) {
+	public function whereStorageId(int $storageId): self {
 		$this->andWhere($this->expr()->eq('storage', $this->createNamedParameter($storageId, IQueryBuilder::PARAM_INT)));
 
 		return $this;
 	}
 
-	public function whereFileId(int $fileId) {
+	public function whereFileId(int $fileId): self {
 		$alias = $this->alias;
 		if ($alias) {
 			$alias .= '.';
@@ -86,7 +86,7 @@ public function wherePath(string $path) {
 		return $this;
 	}
 
-	public function whereParent(int $parent) {
+	public function whereParent(int $parent): self {
 		$alias = $this->alias;
 		if ($alias) {
 			$alias .= '.';
@@ -99,7 +99,7 @@ public function whereParent(int $parent) {
 		return $this;
 	}
 
-	public function whereParentInParameter(string $parameter) {
+	public function whereParentInParameter(string $parameter): self {
 		$alias = $this->alias;
 		if ($alias) {
 			$alias .= '.';
diff --git a/lib/private/Group/Database.php b/lib/private/Group/Database.php
index 62a3990c31999..98d96016d4b2a 100644
--- a/lib/private/Group/Database.php
+++ b/lib/private/Group/Database.php
@@ -464,7 +464,7 @@ public function countDisabledInGroup(string $gid): int {
 		$this->fixDI();
 
 		$query = $this->dbConn->getQueryBuilder();
-		$query->select($query->createFunction('COUNT(DISTINCT ' . $query->getColumnName('uid') . ')'))
+		$query->select($query->func()->countDistinct('uid'))
 			->from('preferences', 'p')
 			->innerJoin('p', 'group_user', 'g', $query->expr()->eq('p.userid', 'g.uid'))
 			->where($query->expr()->eq('appid', $query->createNamedParameter('core')))
diff --git a/lib/private/OpenMetrics/Exporters/ActiveUsers.php b/lib/private/OpenMetrics/Exporters/ActiveUsers.php
index 43425fd37e20f..2c568c89ec825 100644
--- a/lib/private/OpenMetrics/Exporters/ActiveUsers.php
+++ b/lib/private/OpenMetrics/Exporters/ActiveUsers.php
@@ -47,7 +47,7 @@ public function metrics(): Generator {
 		];
 		foreach ($timeFrames as $label => $time) {
 			$qb = $this->connection->getQueryBuilder();
-			$result = $qb->select($qb->createFunction('COUNT(DISTINCT ' . $qb->getColumnName('uid') . ')'))
+			$result = $qb->select($qb->func()->countDistinct('uid'))
 				->from('authtoken')
 				->where($qb->expr()->gte('last_activity', $qb->createNamedParameter($time)))
 				->executeQuery();
diff --git a/lib/public/DB/QueryBuilder/IFunctionBuilder.php b/lib/public/DB/QueryBuilder/IFunctionBuilder.php
index 480ec1cb1ac8c..3b3be6e08596e 100644
--- a/lib/public/DB/QueryBuilder/IFunctionBuilder.php
+++ b/lib/public/DB/QueryBuilder/IFunctionBuilder.php
@@ -105,6 +105,17 @@ public function subtract($x, $y): IQueryFunction;
 	 */
 	public function count($count = '', $alias = ''): IQueryFunction;
 
+	/**
+	 * Get the count of distinct entries.
+	 *
+	 * @param string|ILiteral|IParameter|IQueryFunction $count The input to be counted
+	 * @param string $alias Alias for the counter
+	 *
+	 * @return IQueryFunction
+	 * @since 34.0.0
+	 */
+	public function countDistinct(string|ILiteral|IParameter|IQueryFunction $count = '', string $alias = ''): IQueryFunction;
+
 	/**
 	 * @param string|ILiteral|IParameter|IQueryFunction $field The input to be measured
 	 * @param string $alias Alias for the length
diff --git a/lib/public/DB/QueryBuilder/IQueryBuilder.php b/lib/public/DB/QueryBuilder/IQueryBuilder.php
index b1c483522ee44..846320b562ef0 100644
--- a/lib/public/DB/QueryBuilder/IQueryBuilder.php
+++ b/lib/public/DB/QueryBuilder/IQueryBuilder.php
@@ -11,6 +11,7 @@
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\ParameterType;
 use Doctrine\DBAL\Types\Types;
+use OCP\AppFramework\Attribute\Consumable;
 use OCP\DB\Exception;
 use OCP\DB\IResult;
 use OCP\IDBConnection;
@@ -21,6 +22,7 @@
  *
  * @psalm-taint-specialize
  */
+#[Consumable(since: '8.2.0')]
 interface IQueryBuilder {
 	/**
 	 * @since 9.0.0
@@ -126,7 +128,7 @@ interface IQueryBuilder {
 	 *                      owncloud database prefix automatically.
 	 * @since 8.2.0
 	 */
-	public function automaticTablePrefix($enabled);
+	public function automaticTablePrefix(bool $enabled): void;
 
 	/**
 	 * Gets an ExpressionBuilder used for object-oriented construction of query expressions.
@@ -142,10 +144,9 @@ public function automaticTablePrefix($enabled);
 	 * For more complex expression construction, consider storing the expression
 	 * builder object in a local variable.
 	 *
-	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 * @since 8.2.0
 	 */
-	public function expr();
+	public function expr(): IExpressionBuilder;
 
 	/**
 	 * Gets an FunctionBuilder used for object-oriented construction of query functions.
@@ -161,26 +162,24 @@ public function expr();
 	 * For more complex function construction, consider storing the function
 	 * builder object in a local variable.
 	 *
-	 * @return \OCP\DB\QueryBuilder\IFunctionBuilder
 	 * @since 12.0.0
 	 */
-	public function func();
+	public function func(): IFunctionBuilder;
 
 	/**
 	 * Gets the type of the currently built query.
 	 *
-	 * @return integer
+	 * @deprecated Since 34.0.0, if necessary, track the type of the query being built outside of the builder.
 	 * @since 8.2.0
 	 */
-	public function getType();
+	public function getType(): int;
 
 	/**
 	 * Gets the associated DBAL Connection for this query builder.
 	 *
-	 * @return \OCP\IDBConnection
 	 * @since 8.2.0
 	 */
-	public function getConnection();
+	public function getConnection(): IDBConnection;
 
 	/**
 	 * Gets the state of this query builder instance.
@@ -190,7 +189,7 @@ public function getConnection();
 	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
 	 *    and we can not fix this in our wrapper.
 	 */
-	public function getState();
+	public function getState(): int;
 
 	/**
 	 * Execute for select statements
@@ -229,7 +228,7 @@ public function executeStatement(?IDBConnection $connection = null): int;
 	 * @return string The SQL query string.
 	 * @since 8.2.0
 	 */
-	public function getSQL();
+	public function getSQL(): string;
 
 	/**
 	 * Sets a query parameter for the query being constructed.
@@ -246,10 +245,9 @@ public function getSQL();
 	 * @param mixed $value The parameter value.
 	 * @param string|null|int $type One of the IQueryBuilder::PARAM_* constants.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
-	public function setParameter($key, $value, $type = null);
+	public function setParameter(string|int $key, mixed $value, string|null|int $type = null): self;
 
 	/**
 	 * Sets a collection of query parameters for the query being constructed.
@@ -268,10 +266,9 @@ public function setParameter($key, $value, $type = null);
 	 * @param array $params The query parameters to set.
 	 * @param array $types The query parameters types to set.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
-	public function setParameters(array $params, array $types = []);
+	public function setParameters(array $params, array $types = []): self;
 
 	/**
 	 * Gets all defined query parameters for the query being constructed indexed by parameter index or name.
@@ -279,17 +276,17 @@ public function setParameters(array $params, array $types = []);
 	 * @return array The currently defined query parameters indexed by parameter index or name.
 	 * @since 8.2.0
 	 */
-	public function getParameters();
+	public function getParameters(): array;
 
 	/**
 	 * Gets a (previously set) query parameter of the query being constructed.
 	 *
-	 * @param mixed $key The key (index or name) of the bound parameter.
+	 * @param int|string $key The key (index or name) of the bound parameter.
 	 *
 	 * @return mixed The value of the bound parameter.
 	 * @since 8.2.0
 	 */
-	public function getParameter($key);
+	public function getParameter(int|string $key): mixed;
 
 	/**
 	 * Gets all defined query parameter types for the query being constructed indexed by parameter index or name.
@@ -297,17 +294,17 @@ public function getParameter($key);
 	 * @return array The currently defined query parameter types indexed by parameter index or name.
 	 * @since 8.2.0
 	 */
-	public function getParameterTypes();
+	public function getParameterTypes(): array;
 
 	/**
 	 * Gets a (previously set) query parameter type of the query being constructed.
 	 *
-	 * @param mixed $key The key (index or name) of the bound parameter type.
+	 * @param int|string $key The key (index or name) of the bound parameter type.
 	 *
 	 * @return mixed The value of the bound parameter type.
 	 * @since 8.2.0
 	 */
-	public function getParameterType($key);
+	public function getParameterType(int|string $key): mixed;
 
 	/**
 	 * Sets the position of the first result to retrieve (the "offset").
@@ -317,7 +314,7 @@ public function getParameterType($key);
 	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
-	public function setFirstResult($firstResult);
+	public function setFirstResult(int $firstResult): self;
 
 	/**
 	 * Gets the position of the first result the query object was set to retrieve (the "offset").
@@ -326,17 +323,16 @@ public function setFirstResult($firstResult);
 	 * @return int The position of the first result.
 	 * @since 8.2.0
 	 */
-	public function getFirstResult();
+	public function getFirstResult(): int;
 
 	/**
 	 * Sets the maximum number of results to retrieve (the "limit").
 	 *
 	 * @param int|null $maxResults The maximum number of results to retrieve.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
-	public function setMaxResults($maxResults);
+	public function setMaxResults(?int $maxResults): self;
 
 	/**
 	 * Gets the maximum number of results the query object was set to retrieve (the "limit").
@@ -345,7 +341,7 @@ public function setMaxResults($maxResults);
 	 * @return int|null The maximum number of results.
 	 * @since 8.2.0
 	 */
-	public function getMaxResults();
+	public function getMaxResults(): ?int;
 
 	/**
 	 * Specifies an item that is to be returned in the query result.
@@ -360,12 +356,11 @@ public function getMaxResults();
 	 *
 	 * @param mixed ...$selects The selection expressions.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $selects
 	 */
-	public function select(...$selects);
+	public function select(...$selects): self;
 
 	/**
 	 * Specifies an item that is to be returned with a different name in the query result.
@@ -377,16 +372,15 @@ public function select(...$selects);
 	 *         ->leftJoin('u', 'phonenumbers', 'p', 'u.id = p.user_id');
 	 * </code>
 	 *
-	 * @param mixed $select The selection expressions.
+	 * @param string|IParameter|IQueryFunction $select The selection expressions.
 	 * @param string $alias The column alias used in the constructed query.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.1
 	 *
 	 * @psalm-taint-sink sql $select
 	 * @psalm-taint-sink sql $alias
 	 */
-	public function selectAlias($select, $alias);
+	public function selectAlias(string|IParameter|IQueryFunction $select, string $alias): self;
 
 	/**
 	 * Specifies an item that is to be returned uniquely in the query result.
@@ -397,14 +391,13 @@ public function selectAlias($select, $alias);
 	 *         ->from('users');
 	 * </code>
 	 *
-	 * @param mixed $select The selection expressions.
+	 * @param string|string[] $select The selection expressions.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 9.0.0
 	 *
 	 * @psalm-taint-sink sql $select
 	 */
-	public function selectDistinct($select);
+	public function selectDistinct(string|array $select): self;
 
 	/**
 	 * Adds an item that is to be returned in the query result.
@@ -419,12 +412,11 @@ public function selectDistinct($select);
 	 *
 	 * @param mixed ...$select The selection expression.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $select
 	 */
-	public function addSelect(...$select);
+	public function addSelect(...$selects): self;
 
 	/**
 	 * Turns the query being built into a bulk delete query that ranges over
@@ -438,15 +430,14 @@ public function addSelect(...$select);
 	 * </code>
 	 *
 	 * @param string $delete The table whose rows are subject to the deletion.
-	 * @param string $alias The table alias used in the constructed query.
+	 * @param ?string $alias The table alias used in the constructed query.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 * @since 30.0.0 Alias is deprecated and will no longer be used with the next Doctrine/DBAL update
 	 *
 	 * @psalm-taint-sink sql $delete
 	 */
-	public function delete($delete = null, $alias = null);
+	public function delete(string $delete, ?string $alias = null): self;
 
 	/**
 	 * Turns the query being built into a bulk update query that ranges over
@@ -461,15 +452,14 @@ public function delete($delete = null, $alias = null);
 	 * </code>
 	 *
 	 * @param string $update The table whose rows are subject to the update.
-	 * @param string $alias The table alias used in the constructed query.
+	 * @param ?string $alias The table alias used in the constructed query.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 * @since 30.0.0 Alias is deprecated and will no longer be used with the next Doctrine/DBAL update
 	 *
 	 * @psalm-taint-sink sql $update
 	 */
-	public function update($update = null, $alias = null);
+	public function update(string $update, ?string $alias = null): self;
 
 	/**
 	 * Turns the query being built into an insert query that inserts into
@@ -488,12 +478,11 @@ public function update($update = null, $alias = null);
 	 *
 	 * @param string $insert The table into which the rows should be inserted.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $insert
 	 */
-	public function insert($insert = null);
+	public function insert(string $insert): self;
 
 	/**
 	 * Creates and adds a query root corresponding to the table identified by the
@@ -508,12 +497,11 @@ public function insert($insert = null);
 	 * @param string|IQueryFunction $from The table.
 	 * @param string|null $alias The alias of the table.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $from
 	 */
-	public function from($from, $alias = null);
+	public function from(string|IQueryFunction $from, ?string $alias = null): self;
 
 	/**
 	 * Creates and adds a join to the query.
@@ -530,7 +518,6 @@ public function from($from, $alias = null);
 	 * @param string $alias The alias of the join table.
 	 * @param string|ICompositeExpression|null $condition The condition for the join.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $fromAlias
@@ -538,7 +525,7 @@ public function from($from, $alias = null);
 	 * @psalm-taint-sink sql $alias
 	 * @psalm-taint-sink sql $condition
 	 */
-	public function join($fromAlias, $join, $alias, $condition = null);
+	public function join(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self;
 
 	/**
 	 * Creates and adds a join to the query.
@@ -555,7 +542,6 @@ public function join($fromAlias, $join, $alias, $condition = null);
 	 * @param string $alias The alias of the join table.
 	 * @param string|ICompositeExpression|null $condition The condition for the join.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $fromAlias
@@ -563,7 +549,7 @@ public function join($fromAlias, $join, $alias, $condition = null);
 	 * @psalm-taint-sink sql $alias
 	 * @psalm-taint-sink sql $condition
 	 */
-	public function innerJoin($fromAlias, $join, $alias, $condition = null);
+	public function innerJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self;
 
 	/**
 	 * Creates and adds a left join to the query.
@@ -580,7 +566,6 @@ public function innerJoin($fromAlias, $join, $alias, $condition = null);
 	 * @param string $alias The alias of the join table.
 	 * @param string|ICompositeExpression|null $condition The condition for the join.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 * @since 30.0.0 Allow passing IQueryFunction as parameter for `$join` to allow join with a sub-query.
 	 *
@@ -589,7 +574,7 @@ public function innerJoin($fromAlias, $join, $alias, $condition = null);
 	 * @psalm-taint-sink sql $alias
 	 * @psalm-taint-sink sql $condition
 	 */
-	public function leftJoin($fromAlias, $join, $alias, $condition = null);
+	public function leftJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self;
 
 	/**
 	 * Creates and adds a right join to the query.
@@ -606,7 +591,6 @@ public function leftJoin($fromAlias, $join, $alias, $condition = null);
 	 * @param string $alias The alias of the join table.
 	 * @param string|ICompositeExpression|null $condition The condition for the join.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $fromAlias
@@ -614,7 +598,7 @@ public function leftJoin($fromAlias, $join, $alias, $condition = null);
 	 * @psalm-taint-sink sql $alias
 	 * @psalm-taint-sink sql $condition
 	 */
-	public function rightJoin($fromAlias, $join, $alias, $condition = null);
+	public function rightJoin(string $fromAlias, string|IQueryFunction $join, string $alias, string|ICompositeExpression|null $condition = null): self;
 
 	/**
 	 * Sets a new value for a column in a bulk update query.
@@ -629,13 +613,12 @@ public function rightJoin($fromAlias, $join, $alias, $condition = null);
 	 * @param string $key The column to set.
 	 * @param ILiteral|IParameter|IQueryFunction|string $value The value, expression, placeholder, etc.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $key
 	 * @psalm-taint-sink sql $value
 	 */
-	public function set($key, $value);
+	public function set(string $key, ILiteral|IParameter|IQueryFunction|string $value): self;
 
 	/**
 	 * Specifies one or more restrictions to the query result.
@@ -662,12 +645,11 @@ public function set($key, $value);
 	 *
 	 * @param mixed $predicates The restriction predicates.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $predicates
 	 */
-	public function where(...$predicates);
+	public function where(...$predicates): self;
 
 	/**
 	 * Adds one or more restrictions to the query results, forming a logical
@@ -683,14 +665,12 @@ public function where(...$predicates);
 	 *
 	 * @param mixed ...$where The query restrictions.
 	 *
-	 * @return $this This QueryBuilder instance.
-	 *
 	 * @see where()
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $where
 	 */
-	public function andWhere(...$where);
+	public function andWhere(...$where): self;
 
 	/**
 	 * Adds one or more restrictions to the query results, forming a logical
@@ -706,14 +686,12 @@ public function andWhere(...$where);
 	 *
 	 * @param mixed ...$where The WHERE statement.
 	 *
-	 * @return $this This QueryBuilder instance.
-	 *
 	 * @see where()
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $where
 	 */
-	public function orWhere(...$where);
+	public function orWhere(...$where): self;
 
 	/**
 	 * Specifies a grouping over the results of the query.
@@ -728,12 +706,11 @@ public function orWhere(...$where);
 	 *
 	 * @param mixed ...$groupBys The grouping expression.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $groupBys
 	 */
-	public function groupBy(...$groupBys);
+	public function groupBy(...$groupBys): self;
 
 	/**
 	 * Adds a grouping expression to the query.
@@ -748,12 +725,11 @@ public function groupBy(...$groupBys);
 	 *
 	 * @param mixed ...$groupBy The grouping expression.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $groupby
 	 */
-	public function addGroupBy(...$groupBy);
+	public function addGroupBy(...$groupBy): self;
 
 	/**
 	 * Sets a value for a column in an insert query.
@@ -770,15 +746,14 @@ public function addGroupBy(...$groupBy);
 	 * </code>
 	 *
 	 * @param string $column The column into which the value should be inserted.
-	 * @param IParameter|string $value The value that should be inserted into the column.
+	 * @param IParameter|IQueryFunction|string $value The value that should be inserted into the column.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $column
 	 * @psalm-taint-sink sql $value
 	 */
-	public function setValue($column, $value);
+	public function setValue(string $column, IParameter|IQueryFunction|string $value): self;
 
 	/**
 	 * Specifies values for an insert query indexed by column names.
@@ -795,14 +770,13 @@ public function setValue($column, $value);
 	 *         );
 	 * </code>
 	 *
-	 * @param array $values The values to specify for the insert query indexed by column names.
+	 * @param array<string, IParameter|IFunctionBuilder|string|int> $values The values to specify for the insert query indexed by column names.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $values
 	 */
-	public function values(array $values);
+	public function values(array $values): self;
 
 	/**
 	 * Specifies a restriction over the groups of the query.
@@ -810,12 +784,11 @@ public function values(array $values);
 	 *
 	 * @param mixed ...$having The restriction over the groups.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $having
 	 */
-	public function having(...$having);
+	public function having(...$having): self;
 
 	/**
 	 * Adds a restriction over the groups of the query, forming a logical
@@ -823,12 +796,11 @@ public function having(...$having);
 	 *
 	 * @param mixed ...$having The restriction to append.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $andHaving
 	 */
-	public function andHaving(...$having);
+	public function andHaving(...$having): self;
 
 	/**
 	 * Adds a restriction over the groups of the query, forming a logical
@@ -836,19 +808,18 @@ public function andHaving(...$having);
 	 *
 	 * @param mixed ...$having The restriction to add.
 	 *
-	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
 	 *
 	 * @psalm-taint-sink sql $having
 	 */
-	public function orHaving(...$having);
+	public function orHaving(...$having): self;
 
 	/**
 	 * Specifies an ordering for the query results.
 	 * Replaces any previously specified orderings, if any.
 	 *
 	 * @param string|IQueryFunction|ILiteral|IParameter $sort The ordering expression.
-	 * @param string $order The ordering direction.
+	 * @param 'ASC'|'DESC'|'asc'|'desc'|null $order The ordering direction.
 	 *
 	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
@@ -856,13 +827,13 @@ public function orHaving(...$having);
 	 * @psalm-taint-sink sql $sort
 	 * @psalm-taint-sink sql $order
 	 */
-	public function orderBy($sort, $order = null);
+	public function orderBy(string|IQueryFunction|ILiteral|IParameter $sort, ?string $order = null): self;
 
 	/**
 	 * Adds an ordering to the query results.
 	 *
 	 * @param string|ILiteral|IParameter|IQueryFunction $sort The ordering expression.
-	 * @param string $order The ordering direction.
+	 * @param 'ASC'|'DESC'|'asc'|'desc'|null $order The ordering direction.
 	 *
 	 * @return $this This QueryBuilder instance.
 	 * @since 8.2.0
@@ -870,29 +841,25 @@ public function orderBy($sort, $order = null);
 	 * @psalm-taint-sink sql $sort
 	 * @psalm-taint-sink sql $order
 	 */
-	public function addOrderBy($sort, $order = null);
+	public function addOrderBy(string|ILiteral|IParameter|IQueryFunction $sort, ?string $order = null): self;
 
 	/**
 	 * Gets a query part by its name.
 	 *
-	 * @param string $queryPartName
-	 *
-	 * @return mixed
 	 * @since 8.2.0
 	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
 	 *  and we can not fix this in our wrapper. Please track the details you need, outside the object.
 	 */
-	public function getQueryPart($queryPartName);
+	public function getQueryPart(string $queryPartName): mixed;
 
 	/**
 	 * Gets all query parts.
 	 *
-	 * @return array
 	 * @since 8.2.0
 	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
 	 *  and we can not fix this in our wrapper. Please track the details you need, outside the object.
 	 */
-	public function getQueryParts();
+	public function getQueryParts(): array;
 
 	/**
 	 * Resets SQL parts.
@@ -904,7 +871,7 @@ public function getQueryParts();
 	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
 	 * and we can not fix this in our wrapper. Please create a new IQueryBuilder instead.
 	 */
-	public function resetQueryParts($queryPartNames = null);
+	public function resetQueryParts(?array $queryPartNames = null): self;
 
 	/**
 	 * Resets a single SQL part.
@@ -916,7 +883,7 @@ public function resetQueryParts($queryPartNames = null);
 	 * @deprecated 30.0.0 This function is going to be removed with the next Doctrine/DBAL update
 	 *  and we can not fix this in our wrapper. Please create a new IQueryBuilder instead.
 	 */
-	public function resetQueryPart($queryPartName);
+	public function resetQueryPart(string $queryPartName): self;
 
 	/**
 	 * Creates a new named parameter and bind the value $value to it.
@@ -950,7 +917,7 @@ public function resetQueryPart($queryPartName);
 	 *
 	 * @psalm-taint-escape sql
 	 */
-	public function createNamedParameter($value, $type = self::PARAM_STR, $placeHolder = null);
+	public function createNamedParameter(mixed $value, $type = self::PARAM_STR, ?string $placeHolder = null): IParameter;
 
 	/**
 	 * Creates a new positional parameter and bind the given value to it.
@@ -977,7 +944,7 @@ public function createNamedParameter($value, $type = self::PARAM_STR, $placeHold
 	 *
 	 * @psalm-taint-escape sql
 	 */
-	public function createPositionalParameter($value, $type = self::PARAM_STR);
+	public function createPositionalParameter(mixed $value, $type = self::PARAM_STR): IParameter;
 
 	/**
 	 * Creates a new parameter
@@ -998,7 +965,7 @@ public function createPositionalParameter($value, $type = self::PARAM_STR);
 	 *
 	 * @psalm-taint-escape sql
 	 */
-	public function createParameter($name);
+	public function createParameter(string $name): IParameter;
 
 	/**
 	 * Creates a new function
@@ -1026,7 +993,7 @@ public function createParameter($name);
 	 *
 	 * @psalm-taint-sink sql $call
 	 */
-	public function createFunction($call);
+	public function createFunction(string $call): IQueryFunction;
 
 	/**
 	 * Used to get the id of the last inserted element
@@ -1046,13 +1013,11 @@ public function getLastInsertId(): int;
 	 * @since 9.0.0
 	 * @since 24.0.0 accepts IQueryFunction as parameter
 	 */
-	public function getTableName($table);
+	public function getTableName(string|IQueryFunction $table): string;
 
 	/**
 	 * Returns the table name with database prefix as needed by the implementation
 	 *
-	 * @param string $table
-	 * @return string
 	 * @since 30.0.0
 	 */
 	public function prefixTableName(string $table): string;
@@ -1060,19 +1025,13 @@ public function prefixTableName(string $table): string;
 	/**
 	 * Returns the column name quoted and with table alias prefix as needed by the implementation
 	 *
-	 * @param string $column
-	 * @param string $tableAlias
-	 * @return string
 	 * @since 9.0.0
 	 */
-	public function getColumnName($column, $tableAlias = '');
+	public function getColumnName(string $column, string $tableAlias = ''): string;
 
 	/**
 	 * Provide a hint for the shard key for queries where this can't be detected otherwise
 	 *
-	 * @param string $column
-	 * @param mixed $value
-	 * @return $this
 	 * @since 30.0.0
 	 */
 	public function hintShardKey(string $column, mixed $value, bool $overwrite = false): self;
@@ -1080,7 +1039,6 @@ public function hintShardKey(string $column, mixed $value, bool $overwrite = fal
 	/**
 	 * Set the query to run across all shards if sharding is enabled.
 	 *
-	 * @return $this
 	 * @since 30.0.0
 	 */
 	public function runAcrossAllShards(): self;
@@ -1088,7 +1046,7 @@ public function runAcrossAllShards(): self;
 	/**
 	 * Get a list of column names that are expected in the query output
 	 *
-	 * @return array
+	 * @return string[]
 	 * @since 30.0.0
 	 */
 	public function getOutputColumns(): array;