refactor(database): 优化设备参数值查询逻辑

- 移除 collect_time 字段的查询以提升性能
- 添加 NVL 函数处理空值情况
- 简化查询结果集结构
- 优化数据库查询的执行效率
- 调整字段映射逻辑以符合业务需求

aucma-base/src/main/resources/mapper/base/BaseDeviceParamValMapper.xml

@@ -187,7 +187,6 @@
             SELECT
                 device_code,
                 param_value,
-                collect_time,
                 ROW_NUMBER() OVER (PARTITION BY device_code ORDER BY NVL(record_time, collect_time) DESC) AS rn
             FROM base_device_param_val
             WHERE TRUNC(collect_time) = TRUNC(SYSDATE)
@@ -197,8 +196,7 @@
             d.device_code AS deviceCode,
             d.device_name AS deviceName,
             d.product_line_code AS productLineCode,
-            t.param_value AS startTime,
+            NVL(t.param_value, '') AS startTime
-            t.collect_time AS collectTime
         FROM base_deviceledger d
         LEFT JOIN today_latest t ON d.device_code = t.device_code AND t.rn = 1
         WHERE d.is_flag = 1