From 360114ed42a14e6e292a802a34809e845b54893e Mon Sep 17 00:00:00 2001
From: He Wang <wanghechn@qq.com>
Date: Tue, 13 Jan 2026 17:39:20 +0800
Subject: [PATCH] fix(ob_conn): avoid reusing SQLAlchemy Column objects in DDL
 (#12588)

### What problem does this PR solve?

When there are multiple users, parsing a document for a new user can
trigger the reuse of column objects, leading to the error
`sqlalchemy.exc.ArgumentError: Column object 'id' already assigned to
Table xxx`.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
---
 rag/utils/ob_conn.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rag/utils/ob_conn.py b/rag/utils/ob_conn.py
index d0099a81b..6f6457cda 100644
--- a/rag/utils/ob_conn.py
+++ b/rag/utils/ob_conn.py
@@ -658,7 +658,7 @@ class OBConnection(DocStoreConnection):
 
         self.client.create_table(
             table_name=table_name,
-            columns=column_definitions,
+            columns=[c.copy() for c in column_definitions],
             **table_options,
         )
         logger.info(f"Created table '{table_name}'.")
@@ -711,7 +711,7 @@ class OBConnection(DocStoreConnection):
         try:
             self.client.add_columns(
                 table_name=table_name,
-                columns=[column],
+                columns=[column.copy()],
             )
             logger.info(f"Added column '{column.name}' to table '{table_name}'.")
         except Exception as e: