Do not use fetch join, as even with the N+1 problem the queries are faster than with the very complex and slow expressions needed for the fetch Join pagination

src/DataTables/Adapters/FetchResultsAtOnceORMAdapter.php

@@ -0,0 +1,69 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2023 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/>.
+ */
+
+declare(strict_types=1);
+
+
+namespace App\DataTables\Adapters;
+
+use App\DataTables\Events\ORMPostQueryEvent;
+use Doctrine\ORM\AbstractQuery;
+use Doctrine\ORM\QueryBuilder;
+use Omines\DataTablesBundle\Adapter\AdapterQuery;
+use Omines\DataTablesBundle\Adapter\Doctrine\Event\ORMAdapterQueryEvent;
+use Omines\DataTablesBundle\Adapter\Doctrine\ORMAdapter;
+use Omines\DataTablesBundle\Adapter\Doctrine\ORMAdapterEvents;
+use Omines\DataTablesBundle\Column\AbstractColumn;
+
+/**
+ * This class is very similar to the original ORMAdapter, but instead of getting each line one by one, it gets all the results at once,
+ * which can save some time in combination with fetch hints.
+ */
+class FetchResultsAtOnceORMAdapter extends ORMAdapter
+{
+    protected function getResults(AdapterQuery $query): \Traversable
+    {
+        /** @var QueryBuilder $builder */
+        $builder = $query->get('qb');
+        $state = $query->getState();
+
+        // Apply definitive view state for current 'page' of the table
+        foreach ($state->getOrderBy() as list($column, $direction)) {
+            /** @var AbstractColumn $column */
+            if ($column->isOrderable()) {
+                $builder->addOrderBy($column->getOrderField(), $direction);
+            }
+        }
+        if (null !== $state->getLength()) {
+            $builder
+                ->setFirstResult($state->getStart())
+                ->setMaxResults($state->getLength())
+            ;
+        }
+
+        $q = $builder->getQuery();
+        $event = new ORMAdapterQueryEvent($q);
+        $state->getDataTable()->getEventDispatcher()->dispatch($event, ORMAdapterEvents::PRE_QUERY);
+
+        foreach ($q->getResult() as $item) {
+            yield $item;
+        }
+    }
+}

src/DataTables/PartsDataTable.php

@@ -22,11 +22,16 @@ declare(strict_types=1);
 
 namespace App\DataTables;
 
+use App\DataTables\Adapters\FetchResultsAtOnceORMAdapter;
 use App\DataTables\Column\EnumColumn;
 use App\Entity\Parts\ManufacturingStatus;
+use Doctrine\ORM\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadataInfo;
+use Doctrine\ORM\Query;
+use Omines\DataTablesBundle\Adapter\Doctrine\Event\ORMAdapterQueryEvent;
+use Omines\DataTablesBundle\Adapter\Doctrine\ORMAdapterEvents;
 use Symfony\Bundle\SecurityBundle\Security;
 use App\Entity\Parts\Storelocation;
-use App\DataTables\Adapters\CustomFetchJoinORMAdapter;
 use App\DataTables\Column\EntityColumn;
 use App\DataTables\Column\IconLinkColumn;
 use App\DataTables\Column\LocaleDateTimeColumn;
@@ -43,12 +48,9 @@ use App\DataTables\Helpers\PartDataTableHelper;
 use App\Entity\Parts\Part;
 use App\Entity\Parts\PartLot;
 use App\Services\Formatters\AmountFormatter;
-use App\Services\Attachments\AttachmentURLGenerator;
 use App\Services\EntityURLGenerator;
-use App\Services\Trees\NodesListBuilder;
 use Doctrine\ORM\QueryBuilder;
 use Omines\DataTablesBundle\Adapter\Doctrine\ORM\SearchCriteriaProvider;
-use Omines\DataTablesBundle\Column\MapColumn;
 use Omines\DataTablesBundle\Column\TextColumn;
 use Omines\DataTablesBundle\DataTable;
 use Omines\DataTablesBundle\DataTableTypeInterface;
@@ -267,12 +269,12 @@ final class PartsDataTable implements DataTableTypeInterface
             ])
 
             ->addOrderBy('name')
-            ->createAdapter(CustomFetchJoinORMAdapter::class, [
+            ->createAdapter(FetchResultsAtOnceORMAdapter::class, [
-                'simple_total_query' => true,
                 'query' => function (QueryBuilder $builder): void {
                     $this->getQuery($builder);
                 },
                 'entity' => Part::class,
+                'hydrate' => Query::HYDRATE_OBJECT,
                 'criteria' => [
                     function (QueryBuilder $builder) use ($options): void {
                         $this->buildCriteria($builder, $options);
@@ -280,13 +282,29 @@ final class PartsDataTable implements DataTableTypeInterface
                     new SearchCriteriaProvider(),
                 ],
             ]);
+
+        $dataTable->addEventListener(ORMAdapterEvents::PRE_QUERY, $this->preQueryEventHandler(...));
+    }
+
+    private function preQueryEventHandler(ORMAdapterQueryEvent $event): void
+    {
+        $query = $event->getQuery();
+
+        //Eager fetch the associations of the part entity (we can only fetch toOne associations that way)
+        $query->setFetchMode(Part::class, 'category', ClassMetadataInfo::FETCH_EAGER);
+        $query->setFetchMode(Part::class, 'footprint', ClassMetadata::FETCH_EAGER);
+        $query->setFetchMode(Part::class, 'manufacturer', ClassMetadata::FETCH_EAGER);
+        $query->setFetchMode(Part::class, 'partUnit', ClassMetadata::FETCH_EAGER);
+        $query->setFetchMode(Part::class, 'master_picture_attachment', ClassMetadata::FETCH_EAGER);
     }
 
     private function getQuery(QueryBuilder $builder): void
     {
         //Distinct is very slow here, do not add this here (also I think this is not needed here, as the id column is always distinct)
-        $builder->select('part')
+        $builder
-            ->addSelect('category')
+            //->distinct()
+            ->select('part')
+            /*->addSelect('category')
             ->addSelect('footprint')
             ->addSelect('manufacturer')
             ->addSelect('partUnit')
@@ -295,7 +313,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ->addSelect('partLots')
             ->addSelect('orderdetails')
             ->addSelect('attachments')
-            ->addSelect('storelocations')
+            ->addSelect('storelocations')*/
             //Calculate amount sum using a subquery, so we can filter and sort by it
             ->addSelect(
                 '(
@@ -321,8 +339,9 @@ final class PartsDataTable implements DataTableTypeInterface
             ->leftJoin('part.parameters', 'parameters')
 
             //We have to group by all elements, or only the first sub elements of an association is fetched! (caused issue #190)
-            ->addGroupBy('part')
+            ->addGroupBy('part.id')
-            ->addGroupBy('partLots')
+            //->addGroupBy('part')
+            /*->addGroupBy('partLots')
             ->addGroupBy('category')
             ->addGroupBy('master_picture_attachment')
             ->addGroupBy('storelocations')
@@ -333,7 +352,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ->addGroupBy('suppliers')
             ->addGroupBy('attachments')
             ->addGroupBy('partUnit')
-            ->addGroupBy('parameters')
+            ->addGroupBy('parameters')*/
         ;
     }
 

src/Entity/Parts/PartLot.php

@@ -22,6 +22,7 @@ declare(strict_types=1);
 
 namespace App\Entity\Parts;
 
+use App\Repository\PartLotRepository;
 use Doctrine\DBAL\Types\Types;
 use App\Entity\Base\AbstractDBElement;
 use App\Entity\Base\TimestampTrait;
@@ -79,7 +80,7 @@ class PartLot extends AbstractDBElement implements TimeStampableInterface, Named
      * @var Storelocation|null The storelocation of this lot
      */
     #[Groups(['simple', 'extended', 'full', 'import'])]
-    #[ORM\ManyToOne(targetEntity: Storelocation::class)]
+    #[ORM\ManyToOne(targetEntity: Storelocation::class, fetch: 'EAGER')]
     #[ORM\JoinColumn(name: 'id_store_location')]
     #[Selectable()]
     protected ?Storelocation $storage_location = null;