diff --git a/backend/app/services/product_service.py b/backend/app/services/product_service.py
index 92d8436..59da0df 100644
--- a/backend/app/services/product_service.py
+++ b/backend/app/services/product_service.py
@@ -420,15 +420,15 @@ async def get_all_products(
     overall_names: dict[uuid.UUID, str] = {}
     main_assignees: dict[uuid.UUID, str] = {}
     if product_ids:
-        from sqlalchemy import func as sa_func2, case as sa_case2
-        main_where = sa_func2.and_(
+        from sqlalchemy import and_, or_, func as sa_func, case as sa_case
+        main_where = and_(
             Task.product_id.in_(product_ids),
-            sa_func2.or_(
+            or_(
                 Task.parent_task_id.is_(None),
                 Task.task_type.in_(["TRANSFER", "RECOVERY"]),
             ),
         )
-        prio_expr = sa_case2(
+        prio_expr = sa_case(
             (Task.status == "WIP", 3),
             (Task.status == "PENDING", 2),
             (Task.status == "COMPLETED", 1),
@@ -436,20 +436,20 @@ async def get_all_products(
         )
         # 子查询：每个产品最高优先级主干任务
         max_prio = (
-            select(Task.product_id, sa_func2.max(prio_expr).label("prio"))
+            select(Task.product_id, sa_func.max(prio_expr).label("prio"))
             .where(main_where)
             .group_by(Task.product_id)
         ).subquery("mp")
         # JOIN 回 tasks 拿 task_name + assignee_id（同优先级取最新创建的）
         main_stmt = (
             select(Task.product_id, Task.task_name, Task.assignee_id)
-            .join(max_prio, sa_func2.and_(
+            .join(max_prio, and_(
                 Task.product_id == max_prio.c.product_id,
                 prio_expr == max_prio.c.prio,
             ))
             .where(main_where)
             .order_by(Task.product_id, Task.created_at.desc())
-            .distinct(Task.product_id)  # PostgreSQL DISTINCT ON
+            .distinct(Task.product_id)
         )
         main_result = await db.execute(main_stmt)
         for row in main_result: