diff --git a/mnemo_cards_backend/lib/database/daos/payment_dao.dart b/mnemo_cards_backend/lib/database/daos/payment_dao.dart
index f24bd17..28d8097 100644
--- a/mnemo_cards_backend/lib/database/daos/payment_dao.dart
+++ b/mnemo_cards_backend/lib/database/daos/payment_dao.dart
@@ -51,15 +51,15 @@ class PaymentDao extends DatabaseAccessor<AppDatabase>
     // (database needs to be regenerated to include id in Payment class)
     // Use externalToken if available, otherwise query by unique fields
     if (inserted.externalToken != null && inserted.externalToken!.isNotEmpty) {
-      final result = await (customSelect(
+      final results = await (customSelect(
         'SELECT id FROM payments WHERE external_token = ? LIMIT 1',
         variables: [Variable.withString(inserted.externalToken!)],
         readsFrom: {payments},
-      ).map((row) => row.read<String>('id')).getSingleOrNull());
-      if (result != null) return result;
+      ).map((row) => row.read<String>('id')).get());
+      if (results.isNotEmpty) return results.first;
     }
     // Fallback: query by userId, date, and amount
-    final result = await (customSelect(
+    final results = await (customSelect(
       'SELECT id FROM payments WHERE user_id = ? AND date = ? AND amount = ? ORDER BY created_at DESC LIMIT 1',
       variables: [
         Variable.withString(payment.userId.value),
@@ -67,8 +67,8 @@ class PaymentDao extends DatabaseAccessor<AppDatabase>
         Variable.withString(inserted.amount),
       ],
       readsFrom: {payments},
-    ).map((row) => row.read<String>('id')).getSingleOrNull());
-    if (result != null) return result;
+    ).map((row) => row.read<String>('id')).get());
+    if (results.isNotEmpty) return results.first;
     throw Exception('Failed to retrieve payment ID after creation');
   }
 
@@ -154,7 +154,6 @@ class PaymentDao extends DatabaseAccessor<AppDatabase>
   }
 
   /// Подсчитать платежи пользователя (только активные)
-  @override
   Future<int> countPaymentsByUserId(String userId) async {
     final countExpr = payments.id.count();
     final query = selectOnly(payments)