Fix user deletion to preserve data integrity

Updates the `deleteUser` method to handle foreign key constraints by transferring user-created records to an admin user before deletion, ensuring data integrity and preventing errors.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: a8a78c07-e900-425c-a577-5b4c5894379d
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/a8a78c07-e900-425c-a577-5b4c5894379d/vetH0Gp

replit.md

@@ -75,4 +75,18 @@ Preferred communication style: Simple, everyday language.
 - **Development Server**: Vite dev server
 
 ### Other Integrations
-- **NocoDB Integration**: Configurable for invoice verification and data synchronization.
+- **NocoDB Integration**: Configurable for invoice verification and data synchronization.
+
+## Recent Changes
+
+### August 11, 2025 - User Deletion Fix
+- **Issue**: Foreign key constraint errors when deleting users who created customer orders or other records
+- **Root Cause**: User records were referenced by multiple tables (customer_orders, deliveries, DLC products, etc.)
+- **Solution Implemented**:
+  - Enhanced deleteUser method with database transaction for atomicity
+  - Dynamic admin user lookup instead of hardcoded fallback user
+  - Ownership transfer of all user-created records to existing admin before deletion
+  - Comprehensive handling of all foreign key relationships
+  - Graceful error handling when no admin user exists
+- **Tables Handled**: customer_orders, orders, deliveries, publicities, dlcProducts, tasks, nocodbConfig, userGroups, userRoles
+- **Result**: Safe user deletion while preserving business data integrity

server/storage.ts

@@ -356,8 +356,18 @@ export class DatabaseStorage implements IStorage {
   async deleteUser(id: string): Promise<void> {
     // Use a transaction to ensure atomicity
     await db.transaction(async (tx: typeof db) => {
-      // Transfer ownership of all records created by this user to admin_dev
-      const adminUserId = "admin_dev";
+      // Find an existing admin user to transfer ownership to
+      const adminUser = await tx
+        .select({ id: users.id })
+        .from(users)
+        .where(eq(users.role, "admin"))
+        .limit(1);
+      
+      if (adminUser.length === 0) {
+        throw new Error("Cannot delete user: No admin user found to transfer ownership to");
+      }
+      
+      const adminUserId = adminUser[0].id;
       
       // Update customer orders
       await tx