From 091b9ff70a8d2c2c400d6e5ee596f91ecd654a7e Mon Sep 17 00:00:00 2001
From: "Torsten Schulz (local)" <tsschulz@gmx.net>
Date: Thu, 18 Dec 2025 17:53:24 +0100
Subject: [PATCH] Enhance model synchronization in sequelize.js by adding logic
 to clean up duplicate pg_description entries before and after sync attempts.
 Implement error handling for potential sync failures related to duplicate
 entries, improving robustness and clarity in foreign key management during
 model synchronization.

---
 backend/utils/sequelize.js | 87 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

diff --git a/backend/utils/sequelize.js b/backend/utils/sequelize.js
index 2dee9a6..fb608c1 100644
--- a/backend/utils/sequelize.js
+++ b/backend/utils/sequelize.js
@@ -530,10 +530,95 @@ const syncModelsAlways = async (models) => {
                 
                 console.log(`  🔄 Syncing model ${model.name} with constraints: false`);
                 try {
+                    // Bereinige doppelte pg_description Einträge vor dem Sync, um "mehr als eine Zeile" Fehler zu vermeiden
+                    try {
+                        const tableName = model.tableName;
+                        const schema = model.options?.schema || 'public';
+                        await sequelize.query(`
+                            DO $$
+                            DECLARE
+                                table_oid oid;
+                                dup_count integer;
+                            BEGIN
+                                -- Finde die OID der Tabelle
+                                SELECT oid INTO table_oid
+                                FROM pg_catalog.pg_class c
+                                JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+                                WHERE c.relname = $1
+                                AND n.nspname = $2;
+                                
+                                IF table_oid IS NOT NULL THEN
+                                    -- Entferne doppelte pg_description Einträge, behalte nur den ersten
+                                    DELETE FROM pg_catalog.pg_description d1
+                                    WHERE d1.objoid = table_oid
+                                    AND EXISTS (
+                                        SELECT 1
+                                        FROM pg_catalog.pg_description d2
+                                        WHERE d2.objoid = d1.objoid
+                                        AND d2.objsubid = d1.objsubid
+                                        AND d2.ctid < d1.ctid
+                                    );
+                                    
+                                    GET DIAGNOSTICS dup_count = ROW_COUNT;
+                                END IF;
+                            END $$;
+                        `, {
+                            bind: [tableName, schema]
+                        });
+                    } catch (descError) {
+                        console.warn(`  ⚠️  Could not clean up duplicate pg_description entries for ${model.name}:`, descError.message);
+                    }
+                    
                     await model.sync({ alter: true, force: false, constraints: false });
                 } catch (syncError) {
+                    // Wenn Sequelize einen "mehr als eine Zeile" Fehler hat, bereinige pg_description und versuche erneut
+                    if (syncError.message && (syncError.message.includes('mehr als eine Zeile') || syncError.message.includes('more than one row'))) {
+                        console.log(`  ⚠️  Sequelize encountered duplicate pg_description entries, cleaning up and retrying...`);
+                        try {
+                            const tableName = model.tableName;
+                            const schema = model.options?.schema || 'public';
+                            await sequelize.query(`
+                                DO $$
+                                DECLARE
+                                    table_oid oid;
+                                BEGIN
+                                    -- Finde die OID der Tabelle
+                                    SELECT oid INTO table_oid
+                                    FROM pg_catalog.pg_class c
+                                    JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
+                                    WHERE c.relname = $1
+                                    AND n.nspname = $2;
+                                    
+                                    IF table_oid IS NOT NULL THEN
+                                        -- Entferne doppelte pg_description Einträge, behalte nur den ersten
+                                        DELETE FROM pg_catalog.pg_description d1
+                                        WHERE d1.objoid = table_oid
+                                        AND EXISTS (
+                                            SELECT 1
+                                            FROM pg_catalog.pg_description d2
+                                            WHERE d2.objoid = d1.objoid
+                                            AND d2.objsubid = d1.objsubid
+                                            AND d2.ctid < d1.ctid
+                                        );
+                                    END IF;
+                                END $$;
+                            `, {
+                                bind: [tableName, schema]
+                            });
+                            // Versuche Sync erneut nach Bereinigung
+                            console.log(`  🔄 Retrying sync after cleaning duplicate pg_description entries...`);
+                            await model.sync({ alter: true, force: false, constraints: false });
+                        } catch (retryError) {
+                            console.error(`  ❌ Retry after pg_description cleanup failed:`, retryError.message);
+                            // Kombiniere beide Fehler für besseres Debugging
+                            const combinedError = new Error(`Sync failed: ${syncError.message}. Retry after pg_description cleanup also failed: ${retryError.message}`);
+                            combinedError.originalError = syncError;
+                            combinedError.retryError = retryError;
+                            throw combinedError;
+                        }
+                    }
                     // Wenn Sequelize versucht, Foreign Keys zu erstellen, entferne sie nach dem Fehler
-                    if (syncError.message && syncError.message.includes('REFERENCES')) {
+                    else if (syncError.message && syncError.message.includes('REFERENCES')) {
                         console.log(`  ⚠️  Sequelize tried to create FK despite constraints: false, removing any created FKs...`);
                         try {
                             const tableName = model.tableName;