报错修复v2

@@ -254,7 +254,7 @@ public class ShzzDevicePullService {
                     String deviceName = result.get(1).toString();
 
                     // 查询该设备最近两条key='531'的数据
-                    String tsKvSql = "SELECT str_v FROM ts_kv " +
+                    String tsKvSql = "SELECT long_v FROM ts_kv " +
                             "WHERE entity_id = ? AND key = '531' " +
                             "ORDER BY ts DESC LIMIT 2";
 
@@ -265,7 +265,11 @@ public class ShzzDevicePullService {
 
                     List<String> strVValues = new ArrayList<>(2);
                     while (tsKvResultSet.next()) {
-                        strVValues.add(tsKvResultSet.getString("long_v"));
+                        long value = tsKvResultSet.getLong("long_v");
+                        // 注意：getLong() 如果数据库值为NULL会返回0，这里需要判断是否真的为NULL
+                        if (!tsKvResultSet.wasNull()) {
+                            strVValues.add(String.valueOf(value));
+                        }
                     }
 
                     // 如果查询到两条数据且值不同，才认为是真正的RUN状态