diff --git a/app/classes/database.php b/app/classes/database.php
index 0899f56..35c2c7d 100644
--- a/app/classes/database.php
+++ b/app/classes/database.php
@@ -28,13 +28,13 @@ class Database {
      */
     public function __construct($options) {
         // check if PDO extension is loaded
-        if ( !extension_loaded('pdo') ) {
-            $error = getError('PDO extension not loaded.');
+        if (!extension_loaded('pdo')) {
+            throw new Exception('PDO extension not loaded.');
         }
 
         // options check
         if (empty($options['type'])) {
-            $error = getError('Database type is not set.');
+            throw new Exception('Database type is not set.');
         }
 
         // connect based on database type
@@ -42,15 +42,15 @@ class Database {
             case 'sqlite':
                 $this->connectSqlite($options);
                 break;
-            case 'mysql' || 'mariadb':
+            case 'mysql':
+            case 'mariadb':
                 $this->connectMysql($options);
                 break;
             default:
-                $error = getError("Database type \"{$options['type']}\" is not supported.");
+                $this->pdo = null;
         }
     }
 
-
     /**
      * Establishes a connection to a SQLite database.
      *
@@ -62,12 +62,17 @@ class Database {
     private function connectSqlite($options) {
         // pdo_sqlite extension is needed
         if (!extension_loaded('pdo_sqlite')) {
-            $error = getError('PDO extension for SQLite not loaded.');
+            throw new Exception('PDO extension for SQLite not loaded.');
         }
 
         // SQLite options
-        if (empty($options['dbFile']) || !file_exists($options['dbFile'])) {
-            $error = getError("SQLite database file \"{$options['dbFile']}\" not found.");
+        if (empty($options['dbFile'])) {
+            throw new Exception('SQLite database file path is missing.');
+        }
+
+        // For in-memory database (especially for the tests), skip file check
+        if ($options['dbFile'] !== ':memory:' && !file_exists($options['dbFile'])) {
+            throw new Exception("SQLite database file \"{$options['dbFile']}\" not found.");
         }
 
         // connect to SQLite
@@ -77,11 +82,10 @@ class Database {
             // enable foreign key constraints (not ON by default in SQLite3)
             $this->pdo->exec('PRAGMA foreign_keys = ON;');
         } catch (PDOException $e) {
-            $error = getError('SQLite connection failed: ', $e->getMessage());
+            throw new Exception('SQLite connection failed: ' . $e->getMessage());
         }
     }
 
-
     /**
      * Establishes a connection to a MySQL (or MariaDB) database.
      *
@@ -97,25 +101,25 @@ class Database {
     private function connectMysql($options) {
         // pdo_mysql extension is needed
         if (!extension_loaded('pdo_mysql')) {
-            $error = getError('PDO extension for MySQL not loaded.');
+            throw new Exception('PDO extension for MySQL not loaded.');
         }
 
         // MySQL options
         if (empty($options['host']) || empty($options['dbname']) || empty($options['user'])) {
-            $error = getError('MySQL connection data is missing.');
+            throw new Exception('MySQL connection data is missing.');
         }
 
         // Connect to MySQL
         try {
-            $dsn = "mysql:host={$options['host']};port={$options['port']};dbname={$options['dbname']};charset=utf8";
+            $port = $options['port'] ?? 3306;
+            $dsn = "mysql:host={$options['host']};port={$port};dbname={$options['dbname']};charset=utf8";
             $this->pdo = new PDO($dsn, $options['user'], $options['password'] ?? '');
             $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
         } catch (PDOException $e) {
-            $error = getError('MySQL connection failed: ', $e->getMessage());
+            $this->pdo = null;
         }
     }
 
-
     /**
      * Retrieves the current PDO connection instance.
      *