automatisch auf verrechnet setzen

routes/billing.js

@@ -217,11 +217,18 @@ router.get('/export/csv', requireAdmin, async (req, res) => {
     `, [period]);
 
     // Alle offenen Rechnungen dieser Periode als bezahlt markieren
-    // COLLATE explizit setzen wegen möglichem Collation-Konflikt
-    await db.query(
-      "UPDATE invoices SET status='paid', paid_at=NOW() WHERE period=? COLLATE utf8mb4_unicode_ci AND status='open'",
-      [period]
+    // IDs zuerst laden um Collation-Probleme zu umgehen
+    const [openInvoices] = await db.query(
+      'SELECT id FROM invoices WHERE CONVERT(period USING utf8mb4) = CONVERT(? USING utf8mb4) AND status = ?',
+      [period, 'open']
     );
+    if (openInvoices.length > 0) {
+      const ids = openInvoices.map(r => r.id);
+      await db.query(
+        `UPDATE invoices SET status='paid', paid_at=NOW() WHERE id IN (${ids.join(',')})`,
+        []
+      );
+    }
 
     res.setHeader('Content-Type', 'text/csv; charset=utf-8');
     res.setHeader('Content-Disposition', `attachment; filename="SEPA_${period}.csv"`);