feat: GTSIT 사이트 구축

app/Database.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App;
+
+use PDO;
+use PDOException;
+
+final class Database
+{
+    private static ?PDO $connection = null;
+
+    public static function connection(): PDO
+    {
+        if (self::$connection instanceof PDO) {
+            return self::$connection;
+        }
+
+        $config = config('database');
+        if (empty($config['name']) || empty($config['user'])) {
+            throw new PDOException('Database configuration is unavailable.');
+        }
+
+        $dsn = sprintf(
+            'mysql:host=%s;port=%d;dbname=%s;charset=%s',
+            $config['host'],
+            $config['port'],
+            $config['name'],
+            $config['charset']
+        );
+
+        self::$connection = new PDO($dsn, $config['user'], $config['password'], [
+            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+            PDO::ATTR_EMULATE_PREPARES => false,
+        ]);
+
+        return self::$connection;
+    }
+}