Implemented proof of concept to convert between database types

src/Command/Migrations/DBMigrationCommand.php

@@ -0,0 +1,121 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2026 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\Command\Migrations;
+
+use App\DataTables\Helpers\ColumnSortHelper;
+use App\Entity\Parts\Manufacturer;
+use App\Services\ImportExportSystem\PartKeeprImporter\PKImportHelper;
+use Doctrine\ORM\EntityManagerInterface;
+
+use Doctrine\ORM\Id\AssignedGenerator;
+use Doctrine\ORM\Mapping\ClassMetadata;
+use Doctrine\Persistence\ManagerRegistry;
+use Doctrine\Persistence\ObjectManager;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+#[AsCommand('partdb:migrate-db', 'Migrate the database to a different platform')]
+class DBMigrationCommand extends Command
+{
+    private readonly EntityManagerInterface $sourceEM;
+    private readonly EntityManagerInterface $targetEM;
+
+    public function __construct(private readonly ManagerRegistry $managerRegistry,
+        private readonly PKImportHelper $importHelper,
+    )
+    {
+        $this->sourceEM = $this->managerRegistry->getManager('migration_source');
+        $this->targetEM = $this->managerRegistry->getManager('default');
+
+        parent::__construct();
+    }
+
+    public function execute(InputInterface $input, OutputInterface $output): int
+    {
+        // Example migration logic (to be replaced with actual migration code)
+        $output->writeln('Starting database migration...');
+
+        //Disable all event listeners on target EM to avoid unwanted side effects
+        $eventManager = $this->targetEM->getEventManager();
+        foreach ($eventManager->getAllListeners() as $event => $listeners) {
+            foreach ($listeners as $listener) {
+                $eventManager->removeEventListener($event, $listener);
+            }
+        }
+
+        $output->writeln('Clear target database...');
+        $this->importHelper->purgeDatabaseForImport($this->targetEM, ['internal', 'migration_versions']);
+
+        $metadata = $this->targetEM->getMetadataFactory()->getAllMetadata();
+
+        //First we modify each entity metadata to have an persist cascade on all relations
+        foreach ($metadata as $metadatum) {
+            $entityClass = $metadatum->getName();
+            $output->writeln('Modifying cascade and ID settings for entity: ' . $entityClass);
+
+            foreach ($metadatum->getAssociationNames() as $fieldName) {
+                $mapping = $metadatum->getAssociationMapping($fieldName);
+                $mapping->cascade = array_unique(array_merge($mapping->cascade, ['persist']));
+
+                $metadatum->setIdGeneratorType(ClassMetadata::GENERATOR_TYPE_NONE);
+                $metadatum->setIdGenerator(new AssignedGenerator());
+            }
+        }
+
+
+        //Afterwards we migrate all entities
+        foreach ($metadata as $metadatum) {
+            //skip all superclasses
+            if ($metadatum->isMappedSuperclass) {
+                continue;
+            }
+
+            $entityClass = $metadatum->getName();
+
+            $output->writeln('Migrating entity: ' . $entityClass);
+
+            $repo = $this->sourceEM->getRepository($entityClass);
+            $items = $repo->findAll();
+            foreach ($items as $item) {
+                $this->targetEM->persist($item);
+            }
+            $this->targetEM->flush();
+        }
+
+        //Migrate all manufacturers from source to target
+        /*$manufacturerRepo = $this->sourceEM->getRepository(Manufacturer::class);
+        $manufacturers = $manufacturerRepo->findAll();
+        foreach ($manufacturers as $manufacturer) {
+            $this->targetEM->persist($manufacturer);
+        }
+        $this->targetEM->flush();
+        */
+
+        $output->writeln('Database migration completed successfully.');
+
+        return Command::SUCCESS;
+    }
+}

src/Services/ImportExportSystem/PartKeeprImporter/PKImportHelper.php

@@ -39,10 +39,10 @@ class PKImportHelper
      * Existing users and groups are not purged.
      * This is needed to avoid ID collisions.
      */
-    public function purgeDatabaseForImport(): void
+    public function purgeDatabaseForImport(?EntityManagerInterface $entityManager = null, array $excluded_tables = ['users', 'groups', 'u2f_keys', 'internal', 'migration_versions']): void
     {
         //We use the ResetAutoIncrementORMPurger to reset the auto increment values of the tables. Also it normalizes table names before checking for exclusion.
-        $purger = new ResetAutoIncrementORMPurger($this->em, ['users', 'groups', 'u2f_keys', 'internal', 'migration_versions']);
+        $purger = new ResetAutoIncrementORMPurger($entityManager ?? $this->em, $excluded_tables);
         $purger->purge();
     }