Implement DTO-based PartsDataTable with optimized queries

Co-authored-by: jbtronics <5410681+jbtronics@users.noreply.github.com>

src/DataTables/Adapters/TwoStepORMAdapter.php

@@ -54,6 +54,8 @@ class TwoStepORMAdapter extends ORMAdapter
 
     private \Closure|null $query_modifier = null;
 
+    private \Closure|null $dto_hydrator = null;
+
     public function __construct(?ManagerRegistry $registry = null)
     {
         parent::__construct($registry);
@@ -82,6 +84,10 @@ class TwoStepORMAdapter extends ORMAdapter
         $resolver->setDefault('query_modifier', null);
         $resolver->setAllowedTypes('query_modifier', ['null', \Closure::class]);
 
+        //Add the possibility to use a custom DTO hydrator instead of entity hydration
+        $resolver->setDefault('dto_hydrator', null);
+        $resolver->setAllowedTypes('dto_hydrator', ['null', \Closure::class]);
+
     }
 
     protected function afterConfiguration(array $options): void
@@ -90,6 +96,7 @@ class TwoStepORMAdapter extends ORMAdapter
         $this->detailQueryCallable = $options['detail_query'];
         $this->use_simple_total = $options['simple_total_query'];
         $this->query_modifier = $options['query_modifier'];
+        $this->dto_hydrator = $options['dto_hydrator'];
     }
 
     protected function prepareQuery(AdapterQuery $query): void
@@ -189,9 +196,19 @@ class TwoStepORMAdapter extends ORMAdapter
 
         $detail_query = $detail_qb->getQuery();
 
-        //We pass the results of the detail query to the datatable for view rendering
-        foreach ($detail_query->getResult() as $item) {
-            yield $item;
+        // If a DTO hydrator is configured, use array hydration and build DTOs
+        if ($this->dto_hydrator !== null) {
+            $arrayResults = $detail_query->getArrayResult();
+            $dtos = $this->dto_hydrator->__invoke($arrayResults);
+            foreach ($dtos as $dto) {
+                yield $dto;
+            }
+        } else {
+            // Original behavior: hydrate as entities
+            //We pass the results of the detail query to the datatable for view rendering
+            foreach ($detail_query->getResult() as $item) {
+                yield $item;
+            }
         }
     }
 

src/DataTables/DTO/PartDTO.php

@@ -0,0 +1,409 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\DataTables\DTO;
+
+use App\Entity\Parts\ManufacturingStatus;
+
+/**
+ * Lightweight DTO for PartsDataTable containing only data needed for table rendering.
+ * This avoids loading full Part entities with all relationships, significantly improving performance.
+ * 
+ * The DTO is populated directly from optimized query results, selecting only required fields.
+ */
+class PartDTO
+{
+    /** @var PartLotDTO[] */
+    private array $partLots = [];
+    
+    /** @var int[] */
+    private array $attachmentIds = [];
+    
+    /** @var array<array{id: int, name: string}> */
+    private array $projects = [];
+
+    public function __construct(
+        // Core Part fields
+        public readonly int $id,
+        public readonly string $name,
+        public readonly ?string $ipn,
+        public readonly ?string $description,
+        public readonly float $minamount,
+        public readonly ?string $manufacturer_product_number,
+        public readonly ?float $mass,
+        public readonly ?string $gtin,
+        public readonly string $tags,
+        public readonly bool $favorite,
+        public readonly bool $needs_review,
+        public readonly ?\DateTimeInterface $addedDate,
+        public readonly ?\DateTimeInterface $lastModified,
+        public readonly ?ManufacturingStatus $manufacturing_status,
+        
+        // Related entity IDs and names (pre-joined for display)
+        public readonly ?int $category_id,
+        public readonly ?string $category_name,
+        public readonly ?int $footprint_id,
+        public readonly ?string $footprint_name,
+        public readonly ?int $manufacturer_id,
+        public readonly ?string $manufacturer_name,
+        public readonly ?int $partUnit_id,
+        public readonly ?string $partUnit_name,
+        public readonly ?string $partUnit_unit,
+        public readonly ?int $partCustomState_id,
+        public readonly ?string $partCustomState_name,
+        public readonly ?int $master_picture_attachment_id,
+        public readonly ?string $master_picture_attachment_filename,
+        public readonly ?string $master_picture_attachment_name,
+        public readonly ?int $footprint_attachment_id,
+        public readonly ?int $builtProject_id,
+        public readonly ?string $builtProject_name,
+        
+        // Computed/aggregated fields
+        public readonly float $amountSum,
+        public readonly float $expiredAmountSum,
+        public readonly bool $hasUnknownAmount,
+    ) {
+    }
+
+    // Compatibility methods that match Part entity interface
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+
+    public function isFavorite(): bool
+    {
+        return $this->favorite;
+    }
+
+    public function isNeedsReview(): bool
+    {
+        return $this->needs_review;
+    }
+
+    public function isNotEnoughInstock(): bool
+    {
+        return $this->amountSum < $this->minamount;
+    }
+
+    public function isAmountUnknown(): bool
+    {
+        return $this->hasUnknownAmount;
+    }
+
+    public function getAmountSum(): float
+    {
+        return $this->amountSum;
+    }
+
+    public function getExpiredAmountSum(): float
+    {
+        return $this->expiredAmountSum;
+    }
+
+    /**
+     * Get built project as a simple object compatible with renderer needs
+     */
+    public function getBuiltProject(): ?object
+    {
+        if ($this->builtProject_id === null) {
+            return null;
+        }
+
+        return new class($this->builtProject_id, $this->builtProject_name) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+        };
+    }
+
+    /**
+     * Get part unit as a simple object compatible with renderer needs
+     */
+    public function getPartUnit(): ?object
+    {
+        if ($this->partUnit_id === null) {
+            return null;
+        }
+
+        return new class($this->partUnit_id, $this->partUnit_name, $this->partUnit_unit) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+                private readonly ?string $unit,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+
+            public function getUnit(): ?string
+            {
+                return $this->unit;
+            }
+        };
+    }
+
+    /**
+     * Get category as a simple object compatible with renderer needs
+     */
+    public function getCategory(): ?object
+    {
+        if ($this->category_id === null) {
+            return null;
+        }
+
+        return new class($this->category_id, $this->category_name) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+        };
+    }
+
+    /**
+     * Get footprint as a simple object compatible with renderer needs
+     */
+    public function getFootprint(): ?object
+    {
+        if ($this->footprint_id === null) {
+            return null;
+        }
+
+        return new class($this->footprint_id, $this->footprint_name) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+        };
+    }
+
+    /**
+     * Get manufacturer as a simple object compatible with renderer needs
+     */
+    public function getManufacturer(): ?object
+    {
+        if ($this->manufacturer_id === null) {
+            return null;
+        }
+
+        return new class($this->manufacturer_id, $this->manufacturer_name) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+        };
+    }
+
+    /**
+     * Get part custom state as a simple object compatible with renderer needs
+     */
+    public function getPartCustomState(): ?object
+    {
+        if ($this->partCustomState_id === null) {
+            return null;
+        }
+
+        return new class($this->partCustomState_id, $this->partCustomState_name) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+        };
+    }
+
+    /**
+     * Get master picture attachment as a simple object for rendering
+     */
+    public function getMasterPictureAttachment(): ?object
+    {
+        if ($this->master_picture_attachment_id === null) {
+            return null;
+        }
+
+        return new class($this->master_picture_attachment_id, $this->master_picture_attachment_name, $this->master_picture_attachment_filename) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+                private readonly ?string $filename,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+
+            public function getFilename(): ?string
+            {
+                return $this->filename;
+            }
+        };
+    }
+
+    /**
+     * Get footprint's master picture attachment
+     */
+    public function getFootprintAttachment(): ?object
+    {
+        if ($this->footprint_attachment_id === null) {
+            return null;
+        }
+
+        return new class($this->footprint_attachment_id) {
+            public function __construct(
+                private readonly int $id,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+        };
+    }
+
+    /**
+     * @return PartLotDTO[]
+     */
+    public function getPartLots(): array
+    {
+        return $this->partLots;
+    }
+
+    /**
+     * @param PartLotDTO[] $partLots
+     */
+    public function setPartLots(array $partLots): void
+    {
+        $this->partLots = $partLots;
+    }
+
+    /**
+     * Get attachment IDs for rendering
+     * @return int[]
+     */
+    public function getAttachments(): array
+    {
+        return $this->attachmentIds;
+    }
+
+    /**
+     * @param int[] $attachmentIds
+     */
+    public function setAttachments(array $attachmentIds): void
+    {
+        $this->attachmentIds = $attachmentIds;
+    }
+
+    /**
+     * Get projects where this part is used
+     * @return array<array{id: int, name: string}>
+     */
+    public function getProjects(): array
+    {
+        return $this->projects;
+    }
+
+    /**
+     * @param array<array{id: int, name: string}> $projects
+     */
+    public function setProjects(array $projects): void
+    {
+        $this->projects = $projects;
+    }
+}

src/DataTables/DTO/PartDTOHydrator.php

@@ -0,0 +1,163 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\DataTables\DTO;
+
+use App\Entity\Parts\Part;
+use App\Entity\Parts\PartLot;
+use Doctrine\ORM\EntityManagerInterface;
+use Doctrine\ORM\Query;
+
+/**
+ * Builds PartDTO objects from database query results.
+ * Handles the hydration of lightweight DTOs instead of full Part entities.
+ */
+class PartDTOHydrator
+{
+    public function __construct(
+        private readonly EntityManagerInterface $entityManager,
+    ) {
+    }
+
+    /**
+     * Build PartDTO objects from a query result set.
+     * Expects results from the optimized detail query that selects specific fields.
+     *
+     * @param array $queryResults Array of results from the detail query
+     * @return PartDTO[]
+     */
+    public function hydrateFromQueryResults(array $queryResults): array
+    {
+        $dtos = [];
+        $partLotsGrouped = [];
+        $attachmentsGrouped = [];
+        $projectsGrouped = [];
+
+        // First pass: Group related data by part ID
+        foreach ($queryResults as $row) {
+            $partId = $row['id'];
+
+            // Group part lots by part ID
+            if (isset($row['partLot_id']) && $row['partLot_id'] !== null) {
+                if (!isset($partLotsGrouped[$partId])) {
+                    $partLotsGrouped[$partId] = [];
+                }
+                $lotKey = $row['partLot_id'];
+                if (!isset($partLotsGrouped[$partId][$lotKey])) {
+                    $partLotsGrouped[$partId][$lotKey] = new PartLotDTO(
+                        id: $row['partLot_id'],
+                        storage_location_id: $row['storageLocation_id'] ?? null,
+                        storage_location_name: $row['storageLocation_name'] ?? null,
+                        storage_location_fullPath: $row['storageLocation_fullPath'] ?? null,
+                    );
+                }
+            }
+
+            // Group attachments by part ID
+            if (isset($row['attachment_id']) && $row['attachment_id'] !== null) {
+                if (!isset($attachmentsGrouped[$partId])) {
+                    $attachmentsGrouped[$partId] = [];
+                }
+                $attachmentsGrouped[$partId][$row['attachment_id']] = $row['attachment_id'];
+            }
+
+            // Group projects by part ID
+            if (isset($row['project_id']) && $row['project_id'] !== null) {
+                if (!isset($projectsGrouped[$partId])) {
+                    $projectsGrouped[$partId] = [];
+                }
+                $projectKey = $row['project_id'];
+                if (!isset($projectsGrouped[$partId][$projectKey])) {
+                    $projectsGrouped[$partId][$projectKey] = [
+                        'id' => $row['project_id'],
+                        'name' => $row['project_name'] ?? '',
+                    ];
+                }
+            }
+        }
+
+        // Second pass: Create DTOs (one per part, using first row's data)
+        $processedParts = [];
+        foreach ($queryResults as $row) {
+            $partId = $row['id'];
+
+            // Skip if we've already processed this part
+            if (isset($processedParts[$partId])) {
+                continue;
+            }
+            $processedParts[$partId] = true;
+
+            $dto = new PartDTO(
+                id: $row['id'],
+                name: $row['name'],
+                ipn: $row['ipn'] ?? null,
+                description: $row['description'] ?? null,
+                minamount: $row['minamount'] ?? 0.0,
+                manufacturer_product_number: $row['manufacturer_product_number'] ?? null,
+                mass: $row['mass'] ?? null,
+                gtin: $row['gtin'] ?? null,
+                tags: $row['tags'] ?? '',
+                favorite: $row['favorite'] ?? false,
+                needs_review: $row['needs_review'] ?? false,
+                addedDate: $row['addedDate'] ?? null,
+                lastModified: $row['lastModified'] ?? null,
+                manufacturing_status: $row['manufacturing_status'] ?? null,
+                category_id: $row['category_id'] ?? null,
+                category_name: $row['category_name'] ?? null,
+                footprint_id: $row['footprint_id'] ?? null,
+                footprint_name: $row['footprint_name'] ?? null,
+                manufacturer_id: $row['manufacturer_id'] ?? null,
+                manufacturer_name: $row['manufacturer_name'] ?? null,
+                partUnit_id: $row['partUnit_id'] ?? null,
+                partUnit_name: $row['partUnit_name'] ?? null,
+                partUnit_unit: $row['partUnit_unit'] ?? null,
+                partCustomState_id: $row['partCustomState_id'] ?? null,
+                partCustomState_name: $row['partCustomState_name'] ?? null,
+                master_picture_attachment_id: $row['master_picture_attachment_id'] ?? null,
+                master_picture_attachment_filename: $row['master_picture_attachment_filename'] ?? null,
+                master_picture_attachment_name: $row['master_picture_attachment_name'] ?? null,
+                footprint_attachment_id: $row['footprint_attachment_id'] ?? null,
+                builtProject_id: $row['builtProject_id'] ?? null,
+                builtProject_name: $row['builtProject_name'] ?? null,
+                amountSum: $row['amountSum'] ?? 0.0,
+                expiredAmountSum: $row['expiredAmountSum'] ?? 0.0,
+                hasUnknownAmount: $row['hasUnknownAmount'] ?? false,
+            );
+
+            // Attach grouped data
+            if (isset($partLotsGrouped[$partId])) {
+                $dto->setPartLots(array_values($partLotsGrouped[$partId]));
+            }
+            if (isset($attachmentsGrouped[$partId])) {
+                $dto->setAttachments(array_values($attachmentsGrouped[$partId]));
+            }
+            if (isset($projectsGrouped[$partId])) {
+                $dto->setProjects(array_values($projectsGrouped[$partId]));
+            }
+
+            $dtos[] = $dto;
+        }
+
+        return $dtos;
+    }
+}

src/DataTables/DTO/PartLotDTO.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\DataTables\DTO;
+
+/**
+ * Lightweight data structure representing a Part Lot for table display.
+ * Contains only essential fields needed for rendering storage locations.
+ */
+readonly class PartLotDTO
+{
+    public function __construct(
+        public int $id,
+        public ?int $storage_location_id,
+        public ?string $storage_location_name,
+        public ?string $storage_location_fullPath,
+    ) {
+    }
+
+    public function getStorageLocation(): ?object
+    {
+        if ($this->storage_location_id === null) {
+            return null;
+        }
+
+        // Return a simple object with needed methods for rendering
+        return new class($this->storage_location_id, $this->storage_location_name, $this->storage_location_fullPath) {
+            public function __construct(
+                private readonly int $id,
+                private readonly ?string $name,
+                private readonly ?string $fullPath,
+            ) {
+            }
+
+            public function getId(): int
+            {
+                return $this->id;
+            }
+
+            public function getName(): ?string
+            {
+                return $this->name;
+            }
+
+            public function getFullPath(): ?string
+            {
+                return $this->fullPath;
+            }
+        };
+    }
+}

src/DataTables/Helpers/PartDataTableHelper.php

@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace App\DataTables\Helpers;
 
+use App\DataTables\DTO\PartDTO;
 use App\Entity\Parts\StorageLocation;
 use App\Entity\ProjectSystem\Project;
 use App\Entity\Attachments\Attachment;
@@ -31,6 +32,7 @@ use App\Services\Attachments\AttachmentURLGenerator;
 use App\Services\Attachments\PartPreviewGenerator;
 use App\Services\EntityURLGenerator;
 use App\Services\Formatters\AmountFormatter;
+use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
@@ -44,10 +46,11 @@ class PartDataTableHelper
         private readonly EntityURLGenerator $entityURLGenerator,
         private readonly TranslatorInterface $translator,
         private readonly AmountFormatter $amountFormatter,
+        private readonly EntityManagerInterface $entityManager,
     ) {
     }
 
-    public function renderName(Part $context): string
+    public function renderName($context): string
     {
         $icon = '';
 
@@ -60,22 +63,62 @@ class PartDataTableHelper
             $icon = sprintf('<i class="fa-solid fa-ambulance fa-fw me-1" title="%s"></i>',
                 $this->translator->trans('part.needs_review.badge'));
         }
-        if ($context->getBuiltProject() instanceof Project) {
+        if ($context->getBuiltProject() !== null) {
             $icon = sprintf('<i class="fa-solid fa-box-archive fa-fw me-1" title="%s"></i>',
                 $this->translator->trans('part.info.projectBuildPart.hint').': '.$context->getBuiltProject()->getName());
         }
 
+        // For DTO, create a Part proxy for URL generation
+        $partForUrl = $context;
+        if ($context instanceof PartDTO) {
+            $partForUrl = $this->entityManager->getReference(Part::class, $context->getId());
+        }
 
         return sprintf(
             '<a href="%s">%s%s</a>',
-            $this->entityURLGenerator->infoURL($context),
+            $this->entityURLGenerator->infoURL($partForUrl),
             $icon,
             htmlspecialchars($context->getName())
         );
     }
 
-    public function renderPicture(Part $context): string
+    public function renderPicture($context): string
     {
+        // For DTO, we already have the attachment info, so we can create a lightweight attachment object
+        if ($context instanceof PartDTO) {
+            $preview_attachment = null;
+            
+            // First check if part has a master picture attachment
+            if ($context->master_picture_attachment_id !== null) {
+                $preview_attachment = $this->entityManager->getReference(Attachment::class, $context->master_picture_attachment_id);
+            }
+            // Otherwise check if footprint has a master picture attachment  
+            elseif ($context->footprint_attachment_id !== null) {
+                $preview_attachment = $this->entityManager->getReference(Attachment::class, $context->footprint_attachment_id);
+            }
+            
+            if (!$preview_attachment instanceof Attachment) {
+                return '';
+            }
+            
+            // For DTO we have the name and filename pre-loaded, but we need to access them from the full attachment
+            // Since we're using getReference, we'll get a proxy that will load data on access
+            $title = htmlspecialchars($context->master_picture_attachment_name ?? '');
+            if ($context->master_picture_attachment_filename) {
+                $title .= ' ('.htmlspecialchars($context->master_picture_attachment_filename).')';
+            }
+
+            return sprintf(
+                '<img alt="%s" src="%s" data-thumbnail="%s" class="%s" data-title="%s" data-controller="elements--hoverpic">',
+                'Part image',
+                $this->attachmentURLGenerator->getThumbnailURL($preview_attachment),
+                $this->attachmentURLGenerator->getThumbnailURL($preview_attachment, 'thumbnail_md'),
+                'hoverpic part-table-image',
+                $title
+            );
+        }
+        
+        // Original behavior for Part entities
         $preview_attachment = $this->previewGenerator->getTablePreviewAttachment($context);
         if (!$preview_attachment instanceof Attachment) {
             return '';
@@ -96,26 +139,40 @@ class PartDataTableHelper
         );
     }
 
-    public function renderStorageLocations(Part $context): string
+    public function renderStorageLocations($context): string
     {
         $tmp = [];
+        
+        // For DTO, part lots are already PartLotDTO objects
         foreach ($context->getPartLots() as $lot) {
             //Ignore lots without storelocation
-            if (!$lot->getStorageLocation() instanceof StorageLocation) {
+            $storageLocation = $lot->getStorageLocation();
+            if ($storageLocation === null) {
                 continue;
             }
+            
+            // For DTO, we need to create a StorageLocation reference for URL generation
+            $storageLocationForUrl = $storageLocation;
+            if (!($storageLocation instanceof StorageLocation)) {
+                // The lot DTO returns a simple object, we need a proper reference
+                $storageLocationForUrl = $this->entityManager->getReference(
+                    StorageLocation::class,
+                    $storageLocation->getId()
+                );
+            }
+            
             $tmp[] = sprintf(
                 '<a href="%s" title="%s">%s</a>',
-                $this->entityURLGenerator->listPartsURL($lot->getStorageLocation()),
-                htmlspecialchars($lot->getStorageLocation()->getFullPath()),
-                htmlspecialchars($lot->getStorageLocation()->getName())
+                $this->entityURLGenerator->listPartsURL($storageLocationForUrl),
+                htmlspecialchars($storageLocation->getFullPath() ?? ''),
+                htmlspecialchars($storageLocation->getName() ?? '')
             );
         }
 
         return implode('<br>', $tmp);
     }
 
-    public function renderAmount(Part $context): string
+    public function renderAmount($context): string
     {
         $amount = $context->getAmountSum();
         $expiredAmount = $context->getExpiredAmountSum();

src/DataTables/PartsDataTable.php

@@ -34,6 +34,8 @@ use App\DataTables\Column\RowClassColumn;
 use App\DataTables\Column\SelectColumn;
 use App\DataTables\Column\SIUnitNumberColumn;
 use App\DataTables\Column\TagsColumn;
+use App\DataTables\DTO\PartDTO;
+use App\DataTables\DTO\PartDTOHydrator;
 use App\DataTables\Filters\PartFilter;
 use App\DataTables\Filters\PartSearchFilter;
 use App\DataTables\Helpers\ColumnSortHelper;
@@ -47,6 +49,7 @@ use App\Services\EntityURLGenerator;
 use App\Services\Formatters\AmountFormatter;
 use App\Settings\BehaviorSettings\TableSettings;
 use Doctrine\ORM\AbstractQuery;
+use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\QueryBuilder;
 use Omines\DataTablesBundle\Adapter\Doctrine\ORM\SearchCriteriaProvider;
 use Omines\DataTablesBundle\Column\TextColumn;
@@ -68,6 +71,8 @@ final class PartsDataTable implements DataTableTypeInterface
         private readonly Security $security,
         private readonly ColumnSortHelper $csh,
         private readonly TableSettings $tableSettings,
+        private readonly PartDTOHydrator $partDTOHydrator,
+        private readonly EntityManagerInterface $entityManager,
     ) {
     }
 
@@ -91,7 +96,7 @@ final class PartsDataTable implements DataTableTypeInterface
         $this->csh
             //Color the table rows depending on the review and favorite status
             ->add('row_color', RowClassColumn::class, [
-                'render' => function ($value, Part $context): string {
+                'render' => function ($value, $context): string {
                     if ($context->isNeedsReview()) {
                         return 'table-secondary';
                     }
@@ -106,11 +111,11 @@ final class PartsDataTable implements DataTableTypeInterface
             ->add('picture', TextColumn::class, [
                 'label' => '',
                 'className' => 'no-colvis',
-                'render' => fn($value, Part $context) => $this->partDataTableHelper->renderPicture($context),
+                'render' => fn($value, $context) => $this->partDataTableHelper->renderPicture($context),
             ], visibility_configurable: false)
             ->add('name', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.name'),
-                'render' => fn($value, Part $context) => $this->partDataTableHelper->renderName($context),
+                'render' => fn($value, $context) => $this->partDataTableHelper->renderName($context),
                 'orderField' => 'NATSORT(part.name)'
             ])
             ->add('id', TextColumn::class, [
@@ -142,17 +147,17 @@ final class PartsDataTable implements DataTableTypeInterface
                 'label' => $this->translator->trans('part.table.storeLocations'),
                 //We need to use a aggregate function to get the first store location, as we have a one-to-many relation
                 'orderField' => 'NATSORT(MIN(_storelocations.name))',
-                'render' => fn($value, Part $context) => $this->partDataTableHelper->renderStorageLocations($context),
+                'render' => fn($value, $context) => $this->partDataTableHelper->renderStorageLocations($context),
             ], alias: 'storage_location')
 
             ->add('amount', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.amount'),
-                'render' => fn($value, Part $context) => $this->partDataTableHelper->renderAmount($context),
+                'render' => fn($value, $context) => $this->partDataTableHelper->renderAmount($context),
                 'orderField' => 'amountSum'
             ])
             ->add('minamount', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.minamount'),
-                'render' => fn($value, Part $context): string => htmlspecialchars($this->amountFormatter->format(
+                'render' => fn($value, $context): string => htmlspecialchars($this->amountFormatter->format(
                     $value,
                     $context->getPartUnit()
                 )),
@@ -160,7 +165,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ->add('partUnit', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.partUnit'),
                 'orderField' => 'NATSORT(_partUnit.name)',
-                'render' => function ($value, Part $context): string {
+                'render' => function ($value, $context): string {
                     $partUnit = $context->getPartUnit();
                     if ($partUnit === null) {
                         return '';
@@ -177,7 +182,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ->add('partCustomState', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.partCustomState'),
                 'orderField' => 'NATSORT(_partCustomState.name)',
-                'render' => function($value, Part $context): string {
+                'render' => function($value, $context): string {
                     $partCustomState = $context->getPartCustomState();
 
                     if ($partCustomState === null) {
@@ -202,7 +207,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ->add('manufacturing_status', EnumColumn::class, [
                 'label' => $this->translator->trans('part.table.manufacturingStatus'),
                 'class' => ManufacturingStatus::class,
-                'render' => function (?ManufacturingStatus $status, Part $context): string {
+                'render' => function (?ManufacturingStatus $status, $context): string {
                     if ($status === null) {
                         return '';
                     }
@@ -233,7 +238,7 @@ final class PartsDataTable implements DataTableTypeInterface
         if ($this->security->isGranted('read', Project::class)) {
             $this->csh->add('projects', TextColumn::class, [
                 'label' => $this->translator->trans('project.labelp'),
-                'render' => function ($value, Part $context): string {
+                'render' => function ($value, $context): string {
                     //Only show the first 5 projects names
                     $projects = $context->getProjects();
                     $tmp = "";
@@ -241,8 +246,19 @@ final class PartsDataTable implements DataTableTypeInterface
                     $max = 5;
 
                     for ($i = 0; $i < min($max, count($projects)); $i++) {
-                        $url = $this->urlGenerator->infoURL($projects[$i]);
-                        $tmp .= sprintf('<a href="%s">%s</a>', $url, htmlspecialchars($projects[$i]->getName()));
+                        $project = $projects[$i];
+                        
+                        // For DTO, projects are arrays with id and name
+                        if (is_array($project)) {
+                            $projectProxy = $this->entityManager->getReference(Project::class, $project['id']);
+                            $url = $this->urlGenerator->infoURL($projectProxy);
+                            $tmp .= sprintf('<a href="%s">%s</a>', $url, htmlspecialchars($project['name']));
+                        } else {
+                            // For Part entity, projects are Project objects
+                            $url = $this->urlGenerator->infoURL($project);
+                            $tmp .= sprintf('<a href="%s">%s</a>', $url, htmlspecialchars($project->getName()));
+                        }
+                        
                         if ($i < count($projects) - 1) {
                             $tmp .= ", ";
                         }
@@ -260,8 +276,22 @@ final class PartsDataTable implements DataTableTypeInterface
         $this->csh
             ->add('edit', IconLinkColumn::class, [
                 'label' => $this->translator->trans('part.table.edit'),
-                'href' => fn($value, Part $context) => $this->urlGenerator->editURL($context),
-                'disabled' => fn($value, Part $context) => !$this->security->isGranted('edit', $context),
+                'href' => function ($value, $context) {
+                    // For DTO, get a Part reference for URL generation
+                    if ($context instanceof PartDTO) {
+                        $partProxy = $this->entityManager->getReference(Part::class, $context->getId());
+                        return $this->urlGenerator->editURL($partProxy);
+                    }
+                    return $this->urlGenerator->editURL($context);
+                },
+                'disabled' => function ($value, $context) {
+                    // For DTO, get a Part reference for permission check
+                    if ($context instanceof PartDTO) {
+                        $partProxy = $this->entityManager->getReference(Part::class, $context->getId());
+                        return !$this->security->isGranted('edit', $partProxy);
+                    }
+                    return !$this->security->isGranted('edit', $context);
+                },
                 'title' => $this->translator->trans('part.table.edit.title'),
             ]);
 
@@ -285,6 +315,8 @@ final class PartsDataTable implements DataTableTypeInterface
                     new SearchCriteriaProvider(),
                 ],
                 'query_modifier' => $this->addJoins(...),
+                // Use DTO hydration instead of full entity loading
+                'dto_hydrator' => fn(array $results) => $this->partDTOHydrator->hydrateFromQueryResults($results),
             ]);
     }
 
@@ -312,59 +344,100 @@ final class PartsDataTable implements DataTableTypeInterface
         $ids = array_map(static fn($row) => $row['id'], $filter_results);
 
         /*
-         * In this query we take the IDs which were filtered, paginated and sorted in the filter query, and fetch the
-         * full entities.
-         * We can do complex fetch joins, as we do not need to filter or sort here (which would kill the performance).
-         * The only condition should be for the IDs.
-         * It is important that elements are ordered the same way, as the IDs are passed, or ordering will be wrong.
+         * Optimized query that selects only specific fields needed for table rendering.
+         * Instead of loading full Part entities, we select scalar values and build lightweight DTOs.
+         * This significantly reduces memory usage and improves performance.
          *
-         * We do not require the subqueries like amountSum here, as it is not used to render the table (and only for sorting)
+         * We compute aggregated amounts (amountSum, expiredAmountSum, hasUnknownAmount) using subqueries
+         * to avoid complex PHP iteration.
          */
         $builder
-            ->select('part')
-            ->addSelect('category')
-            ->addSelect('footprint')
-            ->addSelect('manufacturer')
-            ->addSelect('partUnit')
-            ->addSelect('partCustomState')
-            ->addSelect('master_picture_attachment')
-            ->addSelect('footprint_attachment')
-            ->addSelect('partLots')
-            ->addSelect('orderdetails')
-            ->addSelect('attachments')
-            ->addSelect('storelocations')
+            // Core Part fields
+            ->select('part.id AS id')
+            ->addSelect('part.name AS name')
+            ->addSelect('part.ipn AS ipn')
+            ->addSelect('part.description AS description')
+            ->addSelect('part.minamount AS minamount')
+            ->addSelect('part.manufacturer_product_number AS manufacturer_product_number')
+            ->addSelect('part.mass AS mass')
+            ->addSelect('part.gtin AS gtin')
+            ->addSelect('part.tags AS tags')
+            ->addSelect('part.favorite AS favorite')
+            ->addSelect('part.needs_review AS needs_review')
+            ->addSelect('part.addedDate AS addedDate')
+            ->addSelect('part.lastModified AS lastModified')
+            ->addSelect('part.manufacturing_status AS manufacturing_status')
+
+            // Related entity IDs and names
+            ->addSelect('category.id AS category_id')
+            ->addSelect('category.name AS category_name')
+            ->addSelect('footprint.id AS footprint_id')
+            ->addSelect('footprint.name AS footprint_name')
+            ->addSelect('manufacturer.id AS manufacturer_id')
+            ->addSelect('manufacturer.name AS manufacturer_name')
+            ->addSelect('partUnit.id AS partUnit_id')
+            ->addSelect('partUnit.name AS partUnit_name')
+            ->addSelect('partUnit.unit AS partUnit_unit')
+            ->addSelect('partCustomState.id AS partCustomState_id')
+            ->addSelect('partCustomState.name AS partCustomState_name')
+            ->addSelect('master_picture_attachment.id AS master_picture_attachment_id')
+            ->addSelect('master_picture_attachment.filename AS master_picture_attachment_filename')
+            ->addSelect('master_picture_attachment.name AS master_picture_attachment_name')
+            ->addSelect('footprint_attachment.id AS footprint_attachment_id')
+            ->addSelect('builtProject.id AS builtProject_id')
+            ->addSelect('builtProject.name AS builtProject_name')
+
+            // Part lots for storage locations
+            ->addSelect('partLots.id AS partLot_id')
+            ->addSelect('storelocations.id AS storageLocation_id')
+            ->addSelect('storelocations.name AS storageLocation_name')
+            ->addSelect('storelocations.full_path AS storageLocation_fullPath')
+
+            // Attachments
+            ->addSelect('attachments.id AS attachment_id')
+
+            // Projects
+            ->addSelect('projects.id AS project_id')
+            ->addSelect('projects.name AS project_name')
+
+            // Computed/aggregated amounts using subqueries
+            ->addSelect('(
+                SELECT COALESCE(SUM(pl_sum.amount), 0.0)
+                FROM ' . PartLot::class . ' pl_sum
+                WHERE pl_sum.part = part.id
+                AND pl_sum.instock_unknown = false
+                AND (pl_sum.expiration_date IS NULL OR pl_sum.expiration_date > CURRENT_DATE())
+            ) AS amountSum')
+            ->addSelect('(
+                SELECT COALESCE(SUM(pl_exp.amount), 0.0)
+                FROM ' . PartLot::class . ' pl_exp
+                WHERE pl_exp.part = part.id
+                AND pl_exp.instock_unknown = false
+                AND pl_exp.expiration_date IS NOT NULL
+                AND pl_exp.expiration_date <= CURRENT_DATE()
+            ) AS expiredAmountSum')
+            ->addSelect('(
+                SELECT CASE WHEN COUNT(pl_unk.id) > 0 THEN true ELSE false END
+                FROM ' . PartLot::class . ' pl_unk
+                WHERE pl_unk.part = part.id
+                AND pl_unk.instock_unknown = true
+            ) AS hasUnknownAmount')
+
             ->from(Part::class, 'part')
             ->leftJoin('part.category', 'category')
-            ->leftJoin('part.master_picture_attachment', 'master_picture_attachment')
-            ->leftJoin('part.partLots', 'partLots')
-            ->leftJoin('partLots.storage_location', 'storelocations')
             ->leftJoin('part.footprint', 'footprint')
             ->leftJoin('footprint.master_picture_attachment', 'footprint_attachment')
             ->leftJoin('part.manufacturer', 'manufacturer')
-            ->leftJoin('part.orderdetails', 'orderdetails')
-            ->leftJoin('orderdetails.supplier', 'suppliers')
-            ->leftJoin('part.attachments', 'attachments')
             ->leftJoin('part.partUnit', 'partUnit')
             ->leftJoin('part.partCustomState', 'partCustomState')
-            ->leftJoin('part.parameters', 'parameters')
+            ->leftJoin('part.master_picture_attachment', 'master_picture_attachment')
+            ->leftJoin('part.builtProject', 'builtProject')
+            ->leftJoin('part.partLots', 'partLots')
+            ->leftJoin('partLots.storage_location', 'storelocations')
+            ->leftJoin('part.attachments', 'attachments')
+            ->leftJoin('part.projects', 'projects')
             ->where('part.id IN (:ids)')
-            ->setParameter('ids', $ids)
-
-            //We have to group by all elements, or only the first sub elements of an association is fetched! (caused issue #190)
-            ->addGroupBy('part')
-            ->addGroupBy('partLots')
-            ->addGroupBy('category')
-            ->addGroupBy('master_picture_attachment')
-            ->addGroupBy('storelocations')
-            ->addGroupBy('footprint')
-            ->addGroupBy('footprint_attachment')
-            ->addGroupBy('manufacturer')
-            ->addGroupBy('orderdetails')
-            ->addGroupBy('suppliers')
-            ->addGroupBy('attachments')
-            ->addGroupBy('partUnit')
-            ->addGroupBy('partCustomState')
-            ->addGroupBy('parameters');
+            ->setParameter('ids', $ids);
 
         //Get the results in the same order as the IDs were passed
         FieldHelper::addOrderByFieldParam($builder, 'part.id', 'ids');