Fix enum IDs in association mappings

lib/Doctrine/ORM/UnitOfWork.php

@@ -2812,6 +2812,10 @@ public function createEntity($className, array $data, &$hints = [])
                         $joinColumnValue = $data[$srcColumn] ?? null;
 
                         if ($joinColumnValue !== null) {
+                            if ($joinColumnValue instanceof BackedEnum) {
+                                $joinColumnValue = $joinColumnValue->value;
+                            }
+
                             if ($targetClass->containsForeignIdentifier) {
                                 $associatedId[$targetClass->getFieldForColumn($targetColumn)] = $joinColumnValue;
                             } else {

tests/Doctrine/Tests/Models/GH10132/Complex.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10132;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\OneToMany;
+use Doctrine\Tests\Models\Enums\Suit;
+
+/** @Entity */
+class Complex
+{
+    /**
+     * @Id
+     * @Column(type = "string", enumType = Suit::class)
+     */
+    protected Suit $type;
+
+    /** @OneToMany(targetEntity = ComplexChild::class, mappedBy = "complex", cascade = {"persist"}) */
+    protected Collection $complexChildren;
+
+    public function __construct()
+    {
+        $this->complexChildren = new ArrayCollection();
+    }
+
+    public function getType(): Suit
+    {
+        return $this->type;
+    }
+
+    public function setType(Suit $type): void
+    {
+        $this->type = $type;
+    }
+
+    public function getComplexChildren(): Collection
+    {
+        return $this->complexChildren;
+    }
+
+    public function addComplexChild(ComplexChild $complexChild): void
+    {
+        $this->complexChildren->add($complexChild);
+    }
+}

tests/Doctrine/Tests/Models/GH10132/ComplexChild.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10132;
+
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\JoinColumn;
+use Doctrine\ORM\Mapping\ManyToOne;
+use Doctrine\Tests\Models\Enums\Suit;
+
+/** @Entity */
+class ComplexChild
+{
+    /**
+     * @ManyToOne(targetEntity = Complex::class, inversedBy = "complexChildren")
+     * @JoinColumn(name = "complexType", referencedColumnName = "type", nullable = false)
+     */
+    protected Complex $complex;
+
+    /**
+     * @Id
+     * @Column(type = "string", enumType = Suit::class)
+     */
+    protected Suit $complexType;
+
+    public function setComplex(Complex $complex): void
+    {
+        $complex->addComplexChild($this);
+        $this->complexType = $complex->getType();
+        $this->complex     = $complex;
+    }
+
+    public function getComplexType(): Suit
+    {
+        return $this->complexType;
+    }
+
+    public function getComplex(): Complex
+    {
+        return $this->complex;
+    }
+}

tests/Doctrine/Tests/ORM/Functional/Ticket/GH10132Test.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\Tests\Models\Enums\Suit;
+use Doctrine\Tests\Models\GH10132\Complex;
+use Doctrine\Tests\Models\GH10132\ComplexChild;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+/**
+ * @requires PHP 8.1
+ */
+class GH10132Test extends OrmFunctionalTestCase
+{
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->createSchemaForModels(
+            Complex::class,
+            ComplexChild::class
+        );
+    }
+
+    public function testQueryBackedEnumInCompositeKeyJoin(): void
+    {
+        $complex = new Complex();
+        $complex->setType(Suit::Clubs);
+
+        $complexChild = new ComplexChild();
+        $complexChild->setComplex($complex);
+
+        $this->_em->persist($complex);
+        $this->_em->persist($complexChild);
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $qb = $this->_em->createQueryBuilder();
+        $qb->select('s')
+            ->from(ComplexChild::class, 's')
+            ->where('s.complexType = :complexType');
+
+        $qb->setParameter('complexType', Suit::Clubs);
+
+        self::assertNotNull($qb->getQuery()->getOneOrNullResult());
+    }
+}