refactor(api): 重构获取下一编号接口并添加事务处理

- 将路由从@app改为@router以符合FastAPI最佳实践
- 添加事务处理确保数据一致性
- 优化SQL查询逻辑和错误处理
- 改进连接和游标的资源管理

backend/main.py

@@ -400,51 +400,68 @@ def get_l2_model_grades():
         conn.close()
 
 
-@app.get("/api/pdi/next-numbers")
+@router.get("/api/pdi/next-numbers")
 def get_next_numbers():
     """
     获取下一个可用的批次编号和顺序号
     - 批次编号格式: 年月日(6位) + 批次顺序(3位)，如 260406001
     - 顺序号: 当前批次内的最大顺序号+1
     """
-    import datetime
-    conn = get_connection()
-    cursor = conn.cursor()
     try:
         today = datetime.datetime.now().strftime("%y%m%d")
         today_prefix = int(today) * 1000  # 如 260406000
-        
-        # 获取今天最大的批次编号
+
+        # 获取连接
+        conn = get_connection()
+        # 开启事务
+        conn.autocommit = False
+        cursor = conn.cursor()
+
+        # ==============================================
+        # 1. 查询今天已有的最大批次号
+        # ==============================================
         cursor.execute("""
             SELECT MAX(ROLLPROGRAMNB) 
             FROM PLTM.PDI_PLTM 
-            WHERE ROLLPROGRAMNB >= :min_val AND ROLLPROGRAMNB < :max_val
-        """, {"min_val": today_prefix, "max_val": today_prefix + 1000})
+            WHERE ROLLPROGRAMNB BETWEEN :min_val AND :max_val
+        """, {"min_val": today_prefix, "max_val": today_prefix + 999})
+        
         row = cursor.fetchone()
-        max_today_batch = row[0] if row[0] else today_prefix
-        
-        # 计算下一个批次编号
-        next_batch = max_today_batch + 1
-        
-        # 获取当前批次的最大顺序号
+        max_today_batch = row[0] if row[0] is not None else today_prefix
+
+
+        # ==============================================
+        # 3. 查询【当前最大批次】的顺序号
+        # ==============================================
         cursor.execute("""
-            SELECT MAX(SEQUENCENB) 
+            SELECT NVL(MAX(SEQUENCENB), 0) 
             FROM PLTM.PDI_PLTM 
             WHERE ROLLPROGRAMNB = :batch
-        """, {"batch": next_batch})
-        row = cursor.fetchone()
-        max_sequence = row[0] if row[0] else 0
-        next_sequence = max_sequence + 1
+        """, {"batch": max_today_batch})
         
+        max_sequence = cursor.fetchone()[0]
+        next_sequence = max_sequence + 1
+
+        # 提交事务
+        conn.commit()
+
         return {
-            "rollprogramnb": next_batch,
+            "rollprogramnb": max_today_batch,
             "sequencenb": next_sequence,
             "batch_date": today,
             "max_batch_today": max_today_batch if max_today_batch > today_prefix else None
         }
+
     except Exception as e:
-        logger.warning("获取下一编号失败: %s", e)
-        return {"rollprogramnb": None, "sequencenb": 1}
+        # 回滚
+        if 'conn' in locals():
+            conn.rollback()
+        logger.warning("获取下一编号失败: %s", str(e))
+        return {"rollprogramnb": None, "sequencenb": None}
+
     finally:
-        cursor.close()
-        conn.close()
+        # 安全关闭
+        if 'cursor' in locals():
+            cursor.close()
+        if 'conn' in locals():
+            conn.close()