diff --git a/src/AbstractQueryDataReader.php b/src/AbstractQueryDataReader.php
deleted file mode 100644
index 16644f0..0000000
--- a/src/AbstractQueryDataReader.php
+++ /dev/null
@@ -1,334 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Yiisoft\Data\Db;
-
-use Generator;
-use InvalidArgumentException;
-use Yiisoft\Data\Reader\FilterHandlerInterface;
-use Yiisoft\Data\Reader\FilterInterface;
-use Yiisoft\Data\Reader\Sort;
-use Yiisoft\Db\Query\QueryInterface;
-
-use function array_key_first;
-use function is_array;
-
-/**
- * @template TKey as array-key
- * @template TValue as array|object
- *
- * @implements QueryDataReaderInterface<TKey, TValue>
- */
-abstract class AbstractQueryDataReader implements QueryDataReaderInterface
-{
-    private FilterHandler $filterHandler;
-
-    private ?Sort $sort = null;
-    private ?FilterInterface $filter = null;
-    private ?FilterInterface $having = null;
-    /**
-     * @psalm-var non-negative-int|null
-     */
-    private ?int $limit = null;
-    private int $offset = 0;
-
-    /**
-     * @psalm-var non-negative-int|null
-     */
-    private ?int $count = null;
-
-    /**
-     * @var array[]|object[]|null
-     * @psalm-var array<TKey, TValue>|null
-     */
-    private ?array $data = null;
-    private ?int $batchSize = 100;
-    private ?string $countParam = null;
-
-    public function __construct(
-        private QueryInterface $query,
-        ?FilterHandler $filterHandler = null,
-    ) {
-        $this->filterHandler = $filterHandler ?? new FilterHandler();
-    }
-
-    /**
-     * @throws \Throwable
-     * @throws \Yiisoft\Db\Exception\Exception
-     * @throws \Yiisoft\Db\Exception\InvalidConfigException
-     *
-     * @return Generator
-     *
-     * @psalm-return Generator<TKey, TValue, mixed, void>
-     * @psalm-suppress InvalidReturnType
-     */
-    public function getIterator(): Generator
-    {
-        if (is_array($this->data)) {
-            yield from $this->data;
-        } elseif ($this->batchSize === null) {
-            yield from $this->read();
-        } else {
-            $iterator = $this->getPreparedQuery()->each($this->batchSize);
-
-            /** @var array|object $row */
-            foreach ($iterator as $index => $row) {
-                yield $index => $this->createItem($row);
-            }
-        }
-    }
-
-    /**
-     * @throws \Throwable
-     * @throws \Yiisoft\Db\Exception\Exception
-     * @throws \Yiisoft\Db\Exception\InvalidConfigException
-     */
-    public function count(): int
-    {
-        if ($this->count === null) {
-            $q = $this->countParam ?? '*';
-
-            if ($q === '*' && is_array($this->data) && !$this->limit && !$this->offset) {
-                $this->count = count($this->data);
-            } else {
-                $query = $this->getPreparedQuery();
-                $query->offset(null);
-                $query->limit(null);
-                $query->orderBy('');
-
-                /** @psalm-var non-negative-int */
-                $this->count = (int) $query->count($q);
-            }
-        }
-
-        return $this->count;
-    }
-
-    public function getPreparedQuery(): QueryInterface
-    {
-        $query = $this->applyFilter(clone $this->query);
-        $query = $this->applyHaving($query);
-
-        if ($this->limit) {
-            $query->limit($this->limit);
-        }
-
-        if ($this->offset) {
-            $query->offset($this->offset);
-        }
-
-        if ($criteria = $this->sort?->getCriteria()) {
-            $query->addOrderBy($criteria);
-        }
-
-        return $query;
-    }
-
-    protected function applyFilter(QueryInterface $query): QueryInterface
-    {
-        if ($this->filter !== null) {
-            $criteria = $this->filterHandler->handle($this->filter);
-            if ($criteria !== null) {
-                $query = $query->andWhere($criteria->condition, $criteria->params);
-            }
-        }
-
-        return $query;
-    }
-
-    protected function applyHaving(QueryInterface $query): QueryInterface
-    {
-        if ($this->having !== null) {
-            $criteria = $this->filterHandler->handle($this->having);
-            if ($criteria !== null) {
-                $query = $query->andHaving($criteria->condition, $criteria->params);
-            }
-        }
-
-        return $query;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withOffset(int $offset): static
-    {
-        $new = clone $this;
-        $new->data = null;
-        $new->offset = $offset;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withLimit(?int $limit): static
-    {
-        if ($limit < 0) {
-            throw new InvalidArgumentException('$limit must not be less than 0.');
-        }
-
-        $new = clone $this;
-        $new->data = null;
-        $new->limit = $limit;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withCountParam(?string $countParam): static
-    {
-        if ($this->countParam === $countParam) {
-            return $this;
-        }
-
-        $new = clone $this;
-        $new->count = null;
-        $new->countParam = $countParam;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withSort(?Sort $sort): static
-    {
-        $new = clone $this;
-        $new->data = null;
-        $new->sort = $sort;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withFilter(?FilterInterface $filter): static
-    {
-        $new = clone $this;
-        $new->filter = $filter;
-        $new->count = $new->data = null;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withHaving(?FilterInterface $having): static
-    {
-        $new = clone $this;
-        $new->having = $having;
-        $new->count = $new->data = null;
-
-        return $new;
-    }
-
-    /**
-     * @psalm-mutation-free
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withBatchSize(?int $batchSize): static
-    {
-        if ($batchSize !== null && $batchSize < 1) {
-            throw new InvalidArgumentException('$batchSize cannot be less than 1.');
-        }
-
-        $new = clone $this;
-        $new->batchSize = $batchSize;
-
-        return $new;
-    }
-
-    /**
-     * @param FilterHandlerInterface ...$filterHandlers
-     * @return $this
-     *
-     * @psalm-suppress ArgumentTypeCoercion    *
-     * @psalm-return static<TKey, TValue>
-     */
-    public function withAddedFilterHandlers(FilterHandlerInterface ...$filterHandlers): static
-    {
-        $new = clone $this;
-        $new->count = $new->data = null;
-        $new->filterHandler = $this->filterHandler->withFilterHandlers(...$filterHandlers);
-        return $new;
-    }
-
-    public function getSort(): ?Sort
-    {
-        return $this->sort;
-    }
-
-    /**
-     * @psalm-return array<TKey, TValue>
-     *
-     * @throws \Throwable
-     * @throws \Yiisoft\Db\Exception\Exception
-     * @throws \Yiisoft\Db\Exception\InvalidConfigException
-     */
-    public function read(): array
-    {
-        if ($this->data === null) {
-            $this->data = [];
-            /**
-             * @psalm-var TKey $key
-             * @psalm-var array $row
-             */
-            foreach ($this->getPreparedQuery()->all() as $key => $row) {
-                $this->data[$key] = $this->createItem($row);
-            }
-        }
-
-        return $this->data;
-    }
-
-    /**
-     * @throws \Throwable
-     * @throws \Yiisoft\Db\Exception\Exception
-     * @throws \Yiisoft\Db\Exception\InvalidConfigException
-     *
-     * @psalm-return TValue|null
-     */
-    public function readOne(): array|object|null
-    {
-        if (is_array($this->data)) {
-            $key = array_key_first($this->data);
-
-            return $key === null ? null : $this->data[$key];
-        }
-
-        return $this->withLimit(1)->getIterator()->current();
-    }
-
-    /**
-     * @psalm-return TValue
-     */
-    abstract protected function createItem(array|object $row): array|object;
-
-    public function getFilter(): ?FilterInterface
-    {
-        return $this->filter;
-    }
-
-    public function getLimit(): ?int
-    {
-        return $this->limit;
-    }
-
-    public function getOffset(): int
-    {
-        return $this->offset;
-    }
-}
diff --git a/src/QueryDataReader.php b/src/QueryDataReader.php
index fef90be..d014c0f 100644
--- a/src/QueryDataReader.php
+++ b/src/QueryDataReader.php
@@ -4,19 +4,316 @@
 
 namespace Yiisoft\Data\Db;
 
+use Generator;
+use InvalidArgumentException;
+use Yiisoft\Data\Reader\FilterHandlerInterface;
+use Yiisoft\Data\Reader\FilterInterface;
+use Yiisoft\Data\Reader\Sort;
+use Yiisoft\Db\Query\QueryInterface;
+
+use function array_key_first;
+use function count;
+use function is_array;
+
 /**
- * Base class for `QueryDataReaderInterface`
- *
  * @template TKey as array-key
- * @template TValue as array
+ * @template TValue as array|object
  *
- * @extends AbstractQueryDataReader<TKey, TValue>
+ * @implements QueryDataReaderInterface<TKey, TValue>
+ *
+ * @psalm-suppress ClassMustBeFinal This class can be extended.
  */
-final class QueryDataReader extends AbstractQueryDataReader
+class QueryDataReader implements QueryDataReaderInterface
 {
+    private FilterHandler $filterHandler;
+
+    private ?Sort $sort = null;
+    private ?FilterInterface $filter = null;
+    private ?FilterInterface $having = null;
+
+    /**
+     * @psalm-var non-negative-int|null
+     */
+    private ?int $limit = null;
+    private int $offset = 0;
+
+    /**
+     * @psalm-var non-negative-int|null
+     */
+    private ?int $count = null;
+
+    /**
+     * @var array[]|object[]|null
+     * @psalm-var array<TKey, TValue>|null
+     */
+    private ?array $data = null;
+    private ?int $batchSize = 100;
+    private ?string $countParam = null;
+
+    public function __construct(
+        private readonly QueryInterface $query,
+        ?FilterHandler $filterHandler = null,
+    ) {
+        $this->filterHandler = $filterHandler ?? new FilterHandler();
+    }
+
+    /**
+     * @psalm-return Generator<TKey, TValue, mixed, void>
+     * @psalm-suppress InvalidReturnType
+     */
+    final public function getIterator(): Generator
+    {
+        if (is_array($this->data)) {
+            yield from $this->data;
+        } elseif ($this->batchSize === null) {
+            yield from $this->read();
+        } else {
+            $iterator = $this->getPreparedQuery()->each($this->batchSize);
+
+            /** @var array|object $row */
+            foreach ($iterator as $index => $row) {
+                yield $index => $this->createItem($row);
+            }
+        }
+    }
+
+    final public function count(): int
+    {
+        if ($this->count === null) {
+            $q = $this->countParam ?? '*';
+
+            if ($q === '*' && is_array($this->data) && !$this->limit && !$this->offset) {
+                $this->count = count($this->data);
+            } else {
+                $query = $this->getPreparedQuery();
+                $query->offset(null);
+                $query->limit(null);
+                $query->orderBy('');
+
+                /** @psalm-var non-negative-int */
+                $this->count = (int) $query->count($q);
+            }
+        }
+
+        return $this->count;
+    }
+
+    final public function getPreparedQuery(): QueryInterface
+    {
+        $query = $this->applyFilter(clone $this->query);
+        $query = $this->applyHaving($query);
+
+        if ($this->limit) {
+            $query->limit($this->limit);
+        }
+
+        if ($this->offset) {
+            $query->offset($this->offset);
+        }
+
+        if ($criteria = $this->sort?->getCriteria()) {
+            $query->addOrderBy($criteria);
+        }
+
+        return $query;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withOffset(int $offset): static
+    {
+        $new = clone $this;
+        $new->data = null;
+        $new->offset = $offset;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withLimit(?int $limit): static
+    {
+        if ($limit < 0) {
+            throw new InvalidArgumentException('$limit must not be less than 0.');
+        }
+
+        $new = clone $this;
+        $new->data = null;
+        $new->limit = $limit;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withCountParam(?string $countParam): static
+    {
+        if ($this->countParam === $countParam) {
+            return $this;
+        }
+
+        $new = clone $this;
+        $new->count = null;
+        $new->countParam = $countParam;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withSort(?Sort $sort): static
+    {
+        $new = clone $this;
+        $new->data = null;
+        $new->sort = $sort;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withFilter(?FilterInterface $filter): static
+    {
+        $new = clone $this;
+        $new->filter = $filter;
+        $new->count = $new->data = null;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withHaving(?FilterInterface $having): static
+    {
+        $new = clone $this;
+        $new->having = $having;
+        $new->count = $new->data = null;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-mutation-free
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withBatchSize(?int $batchSize): static
+    {
+        if ($batchSize !== null && $batchSize < 1) {
+            throw new InvalidArgumentException('$batchSize cannot be less than 1.');
+        }
+
+        $new = clone $this;
+        $new->batchSize = $batchSize;
+
+        return $new;
+    }
+
+    /**
+     * @psalm-return static<TKey, TValue>
+     */
+    final public function withAddedFilterHandlers(FilterHandlerInterface ...$filterHandlers): static
+    {
+        $new = clone $this;
+        $new->count = $new->data = null;
+        $new->filterHandler = $this->filterHandler->withFilterHandlers(...$filterHandlers);
+        return $new;
+    }
+
+    final public function getSort(): ?Sort
+    {
+        return $this->sort;
+    }
+
+    /**
+     * @psalm-return array<TKey, TValue>
+     */
+    final public function read(): array
+    {
+        if ($this->data === null) {
+            $this->data = [];
+            /**
+             * @psalm-var TKey $key
+             * @psalm-var array $row
+             */
+            foreach ($this->getPreparedQuery()->all() as $key => $row) {
+                $this->data[$key] = $this->createItem($row);
+            }
+        }
+
+        return $this->data;
+    }
+
+    /**
+     * @psalm-return TValue|null
+     */
+    final public function readOne(): array|object|null
+    {
+        if (is_array($this->data)) {
+            $key = array_key_first($this->data);
+
+            return $key === null ? null : $this->data[$key];
+        }
+
+        return $this->withLimit(1)->getIterator()->current();
+    }
+
+    final public function getFilter(): ?FilterInterface
+    {
+        return $this->filter;
+    }
+
+    final public function getLimit(): ?int
+    {
+        return $this->limit;
+    }
+
+    final public function getOffset(): int
+    {
+        return $this->offset;
+    }
+
+    /**
+     * @psalm-return TValue
+     */
     protected function createItem(array|object $row): array|object
     {
         /** @psalm-var TValue */
         return $row;
     }
+
+    private function applyFilter(QueryInterface $query): QueryInterface
+    {
+        if ($this->filter !== null) {
+            $criteria = $this->filterHandler->handle($this->filter);
+            if ($criteria !== null) {
+                $query = $query->andWhere($criteria->condition, $criteria->params);
+            }
+        }
+
+        return $query;
+    }
+
+    private function applyHaving(QueryInterface $query): QueryInterface
+    {
+        if ($this->having !== null) {
+            $criteria = $this->filterHandler->handle($this->having);
+            if ($criteria !== null) {
+                $query = $query->andHaving($criteria->condition, $criteria->params);
+            }
+        }
+
+        return $query;
+    }
 }
diff --git a/tests/Support/CustomerDataReader.php b/tests/Support/CustomerDataReader.php
index a2f33b6..72f5596 100644
--- a/tests/Support/CustomerDataReader.php
+++ b/tests/Support/CustomerDataReader.php
@@ -4,9 +4,9 @@
 
 namespace Yiisoft\Data\Db\Tests\Support;
 
-use Yiisoft\Data\Db\AbstractQueryDataReader;
+use Yiisoft\Data\Db\QueryDataReader;
 
-final class CustomerDataReader extends AbstractQueryDataReader
+final class CustomerDataReader extends QueryDataReader
 {
     protected function createItem(object|array $row): array|object
     {