From b5c523ab0738c6fb6b4e5f85f0584dcf9c0be508 Mon Sep 17 00:00:00 2001
From: Johannes Baumeister <jba@enwelo.de>
Date: Wed, 29 Apr 2026 21:25:58 +0200
Subject: [PATCH] Fix SQL query handling empty string for NULL columns

---
 server.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/server.js b/server.js
index 3830453..1b61a5d 100644
--- a/server.js
+++ b/server.js
@@ -149,9 +149,11 @@ app.post('/api/sicherung', async (req, res) => {
             throw new Error(`Projekt '${projekt_id}' konnte nicht gefunden werden.`);
         }
 
-        // 2. FSKs für den Namen finden
+        // 2. FSKs für den Namen finden (Behandlung von NULL vs leerem String)
         const ownerRes = await client.query(
-            `SELECT "FSK" FROM ${schema}.flaecheneigentuemer_alkis WHERE "GNA" = $1 AND "VNA" = $2`,
+            `SELECT "FSK" FROM ${schema}.flaecheneigentuemer_alkis 
+             WHERE ("GNA" = $1 OR ("GNA" IS NULL AND $1 = '')) 
+               AND ("VNA" = $2 OR ("VNA" IS NULL AND $2 = ''))`,
             [nachname, vorname]
         );