回答です

answer/Ex05.php

@@ -0,0 +1,45 @@
+<?php
+// Ex05.php
+
+require_once __DIR__ . '/Ex05_query.php';
+
+$joinData = getJoinData();
+?>
+<!DOCTYPE html>
+<html>
+
+<head>
+    <meta charset="UTF-8">
+    <title>JOIN Query Result</title>
+    <link href="../common/css/bootstrap.min.css" rel="stylesheet">
+</head>
+
+<body>
+    <div class="container">
+        <h1>JOINによるSELECTクエリの実行 結果</h1>
+        <?php if (!empty($joinData)): ?>
+            <table class="table table-bordered">
+                <thead>
+                    <tr>
+                        <th>従業員名</th>
+                        <th>部署名</th>
+                        <th>プロジェクト名</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <?php foreach ($joinData as $row): ?>
+                        <tr>
+                            <td><?php echo htmlspecialchars($row['employee_name']); ?></td>
+                            <td><?php echo htmlspecialchars($row['department_name']); ?></td>
+                            <td><?php echo htmlspecialchars($row['project_name']); ?></td>
+                        </tr>
+                    <?php endforeach; ?>
+                </tbody>
+            </table>
+        <?php else: ?>
+            <p>データがありません。</p>
+        <?php endif; ?>
+    </div>
+</body>
+
+</html>