fix: handling of empty array in SQL condition generation

Author: Elliot Bruneel

src/Persisters/Entity/BasicEntityPersister.php

@@ -1753,6 +1753,11 @@ public function getSelectConditionStatementSQL($field, $value, $assoc = null, $c
                     $value = [$value];
                 }
 
+                if (empty($value)) {
+                    $selectedColumns[] = $column . ' IN (NULL)';
+                    continue;
+                }
+
                 $nullKeys      = array_keys($value, null, true);
                 $nonNullValues = array_diff_key($value, array_flip($nullKeys));
 

tests/Tests/ORM/Functional/Ticket/GH12254Test.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\GeneratedValue;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+class GH12254Test extends OrmFunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->setUpEntitySchema([
+            GH12254EntityA::class,
+        ]);
+
+        $this->_em->persist(new GH12254EntityA());
+        $this->_em->flush();
+        $this->_em->clear();
+    }
+
+    public function testFindByEmptyArrayShouldReturnEmptyArray(): void
+    {
+        // pretend we are starting afresh
+        $this->_em = $this->getEntityManager();
+        $result = $this->_em->getRepository(GH12254EntityA::class)->findBy(['id' => []]);
+        $this->assertEmpty($result);
+    }
+}
+
+/**
+ * @Entity()
+ */
+class GH12254EntityA
+{
+    /**
+     * @Column(type="integer")
+     * @Id()
+     * @GeneratedValue(strategy="AUTO")
+     * @var int
+     */
+    public $id;
+}

tests/Tests/ORM/Persisters/BasicEntityPersisterTypeValueSqlTest.php

@@ -153,6 +153,15 @@ public function testSelectConditionStatementWithMultipleValuesContainingNull():
         );
     }
 
+    /** @group GH12254 */
+    public function testSelectConditionStatementWithValuesIsEmptyArray(): void
+    {
+        self::assertEquals(
+            't0.id IN (NULL)',
+            $this->persister->getSelectConditionStatementSQL('id', [])
+        );
+    }
+
     public function testCountCondition(): void
     {
         $persister = new BasicEntityPersister($this->entityManager, $this->entityManager->getClassMetadata(NonAlphaColumnsEntity::class));