From c849b0e3e50a0e49db629bee0e20aa98404cf271 Mon Sep 17 00:00:00 2001
From: Javakky <javakky@pixiv.co.jp>
Date: Tue, 20 Jan 2026 17:59:48 +0900
Subject: [PATCH] feat: Support PDO::FETCH_KEY_PAIR

---
 src/FakePdoStatementTrait.php | 34 +++++++++++++++++++++++++++++
 tests/EndToEndTest.php        | 40 +++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/src/FakePdoStatementTrait.php b/src/FakePdoStatementTrait.php
index ce33ca36..dcf0de17 100644
--- a/src/FakePdoStatementTrait.php
+++ b/src/FakePdoStatementTrait.php
@@ -508,6 +508,40 @@ function ($row) use ($fetch_argument, $ctor_args) {
             );
         }
 
+        if ($fetch_style === \PDO::FETCH_KEY_PAIR) {
+            if (!$this->result) {
+                return [];
+            }
+
+            /** @var array<array-key, mixed> $output */
+            $output = [];
+
+            foreach ($this->result as $row) {
+                if ($this->conn->shouldStringifyResult()) {
+                    $row = self::stringify($row);
+                }
+
+                /** @var list<?scalar> $values */
+                $values = \array_values($row);
+
+                if (\count($values) < 2) {
+                    throw new \PDOException('PDO::FETCH_KEY_PAIR requires at least two columns');
+                }
+
+                $key = $values[0];
+
+                if (\is_int($key) || \is_string($key)) {
+                    $output[$key] = $values[1];
+                } elseif ($key === null) {
+                    $output[''] = $values[1];
+                } else {
+                    $output[(int) $key] = $values[1];
+                }
+            }
+
+            return $output;
+        }
+
         throw new \Exception('Fetch style not implemented');
     }
 
diff --git a/tests/EndToEndTest.php b/tests/EndToEndTest.php
index d2cd95a3..96f6cde8 100644
--- a/tests/EndToEndTest.php
+++ b/tests/EndToEndTest.php
@@ -95,6 +95,46 @@ public function testSelectFetchAssoc()
         );
     }
 
+    public function testSelectFetchKeyPair()
+    {
+        $pdo = self::getConnectionToFullDB();
+
+        $query = $pdo->prepare("SELECT id, name FROM `video_game_characters` WHERE `id` > :id ORDER BY `id` ASC");
+        $query->bindValue(':id', 14);
+        $query->execute();
+
+        $this->assertSame(
+            [
+                '15' => 'link',
+                '16' => 'dude'
+            ],
+            $query->fetchAll(\PDO::FETCH_KEY_PAIR)
+        );
+    }
+
+    public function testSelectFetchKeyPairWithVariousKeyTypes()
+    {
+        $pdo = self::getConnectionToFullDB(false);
+
+        $query = $pdo->prepare(
+            "SELECT 1.5, 'foo'
+            UNION ALL SELECT NULL, 'bar'
+            UNION ALL SELECT false, 'baz'
+            UNION ALL SELECT 2, 'qux'"
+        );
+        $query->execute();
+
+        $this->assertEqualsCanonicalizing(
+            [
+                1 => 'foo', // 1.5 -> 1
+                '' => 'bar', // NULL -> ''
+                0 => 'baz', // false -> 0
+                2 => 'qux', // 2 -> 2
+            ],
+            $query->fetchAll(\PDO::FETCH_KEY_PAIR)
+        );
+    }
+
     public function testSelectFetchAssocConverted()
     {
         $pdo = self::getConnectionToFullDB(false);