diff --git a/Engine/Modules/Core/Helper/DoctrineHelper.php b/Engine/Modules/Core/Helper/DoctrineHelper.php
new file mode 100644
index 000000000..cba5f1b8f
--- /dev/null
+++ b/Engine/Modules/Core/Helper/DoctrineHelper.php
@@ -0,0 +1,96 @@
+<?php
+
+namespace Oforge\Engine\Modules\Core\Helper;
+
+use InvalidArgumentException;
+use Oforge\Engine\Modules\Core\Abstracts\AbstractModel;
+
+/**
+ * Class DoctrineHelper
+ *
+ * @package Oforge\Engine\Modules\Core\Helper
+ */
+class DoctrineHelper
+{
+
+    /** Prevent instance. */
+    public function __construct()
+    {
+    }
+
+    /**
+     * @param AbstractModel[] $entities
+     * @param string $valueMethod
+     * @param bool $removeDuplicates
+     *
+     * @return array
+     */
+    public static function propertyValues(array $entities, string $valueMethod, bool $removeDuplicates = false) : array
+    {
+        $result  = [];
+        $checked = false;
+        foreach ($entities as $entity) {
+            if ( !$checked && !method_exists($entity, $valueMethod)) {
+                throw new InvalidArgumentException("Value method '$valueMethod' does not exist.");
+            }
+            $checked  = true;
+            $result[] = $entity->$valueMethod();
+        }
+        if ($removeDuplicates) {
+            $result = array_unique($result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * @param AbstractModel[] $entities
+     * @param string $keyMethod
+     * @param string|null $valueMethod
+     *
+     * @return array
+     */
+    public static function map(array $entities, string $keyMethod, ?string $valueMethod = null) : array
+    {
+        $result  = [];
+        $checked = false;
+        foreach ($entities as $entity) {
+            if ( !$checked) {
+                if ( !method_exists($entity, $keyMethod)) {
+                    throw new InvalidArgumentException("Key method '$keyMethod' does not exist.");
+                }
+                if ($valueMethod !== null && !method_exists($entity, $valueMethod)) {
+                    throw new InvalidArgumentException("Value method '$valueMethod' does not exist.");
+                }
+            }
+            $key   = $entity->$keyMethod();
+            $value = $valueMethod === null ? $entity : $entity->$valueMethod();
+            if ($checked || is_int($key) || is_string($key)) {
+                $result[$key] = $value;
+                $checked      = true;
+            } else {
+                throw new InvalidArgumentException("Key value of '$keyMethod' is no int or string.");
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * @param AbstractModel[] $entities
+     * @param int $maxDepth
+     * @param array $excludeProperties
+     *
+     * @return array
+     */
+    public static function toArray(array $entities, int $maxDepth = 2, array $excludeProperties = []) : array
+    {
+        $result = [];
+        foreach ($entities as $entity) {
+            $result[] = $entity->toArray($maxDepth, $excludeProperties);
+        }
+
+        return $result;
+    }
+
+}