Use a own column type for entities.

src/DataTables/Column/EntityColumn.php

@@ -0,0 +1,65 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 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 General Public License
+ * as published by the Free Software Foundation; either version 2
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\DataTables\Column;
+
+
+use App\Entity\Base\NamedDBElement;
+use Omines\DataTablesBundle\Column\AbstractColumn;
+use Symfony\Component\OptionsResolver\Options;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+class EntityColumn extends AbstractColumn
+{
+
+    /**
+     * The normalize function is responsible for converting parsed and processed data to a datatables-appropriate type.
+     *
+     * @param mixed $value The single value of the column
+     * @return mixed
+     */
+    public function normalize($value)
+    {
+        /** @var NamedDBElement $value */
+        return $value;
+    }
+
+    public function configureOptions(OptionsResolver $resolver)
+    {
+        parent::configureOptions($resolver);
+
+        $resolver->setRequired('property');
+
+        $resolver->setDefault('field', function (Options $option) {
+            return $option['property'] . '.name';
+        });
+    }
+}

src/DataTables/PartsDataTable.php

@@ -29,6 +29,7 @@
 
 namespace App\DataTables;
 
+use App\DataTables\Column\EntityColumn;
 use App\DataTables\Column\LocaleDateTimeColumn;
 use App\Entity\Parts\Category;
 use App\Entity\Parts\Part;
@@ -114,16 +115,16 @@ class PartsDataTable implements DataTableTypeInterface
             ->add('description', TextColumn::class, [
                 'label' => $this->translator->trans('part.table.description'),
             ])
-            ->add('category', TextColumn::class, [
-                'field' => 'category.name',
-                'label' => $this->translator->trans('part.table.category')
+            ->add('category', EntityColumn::class, [
+                'label' => $this->translator->trans('part.table.category'),
+                'property' => 'category'
             ])
-            ->add('footprint', TextColumn::class, [
-                'field' => 'footprint.name',
+            ->add('footprint', EntityColumn::class, [
+                'property' => 'footprint',
                 'label' => $this->translator->trans('part.table.footprint')
             ])
-            ->add('manufacturer', TextColumn::class, [
-                'field' => 'manufacturer.name',
+            ->add('manufacturer', EntityColumn::class, [
+                'property' => 'manufacturer',
                 'label' => $this->translator->trans('part.table.manufacturer')
             ])
             //->add('footprint', TextColumn::class, ['field' => 'footprint.name'])