回答です

answer/Ex02_query.php

@@ -0,0 +1,21 @@
+<?php
+// Ex02_query.php (Answer)
+
+function getEmployees()
+{
+    $dsn = "mysql:host=localhost;dbname=employee_db;charset=utf8";
+    $username = "rezouser";
+    $password = "Rezo_0000";
+    try {
+        $pdo = new PDO($dsn, $username, $password);
+        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $stmt = $pdo->query("SELECT * FROM employees");
+        $results = $stmt->fetchAll(PDO::FETCH_ASSOC);
+        return $results;
+    } catch (PDOException $e) {
+        // エラーが発生した場合は例外メッセージを返すか、空の配列を返す
+        return [];
+    } finally {
+        $pdo = null;
+    }
+}