diff --git a/Service/AlarmService.cs b/Service/AlarmService.cs
index 189f51e..9e0a01d 100644
--- a/Service/AlarmService.cs
+++ b/Service/AlarmService.cs
@@ -396,10 +396,10 @@ namespace LY.App.Service
                     GROUP BY batch_id ORDER BY batch_id desc  LIMIT {1},{2}
                 ) AS CountTable ";
 
-            string tablesql = string.Join(" UNION ALL ", tables.Select(item => $"SELECT batch_id FROM {item.TableName} "));
+            string tablesql = string.Join(" UNION ALL ", tables.Select(item => $"SELECT batch_id FROM {item.TableName}  Group By batch_id "));
             if (!string.IsNullOrEmpty(input.sn))
             {
-                tablesql = string.Join(" UNION ALL ", tables.Select(item => $"SELECT batch_id FROM {item.TableName}  where serial_number  like  '%{input.sn}%' "));
+                tablesql = string.Join(" UNION ALL ", tables.Select(item => $"SELECT batch_id FROM {item.TableName}  where serial_number  like  '%{input.sn}%'  Group By batch_id"));
             }
             var pageitem = await _db.Ado.SqlQueryAsync<int, long>(string.Format(coutsql, tablesql) + string.Format(page, tablesql, (input.pageNum - 1) * input.pageSize, input.pageSize));
 
@@ -413,7 +413,7 @@ namespace LY.App.Service
                     endTime = SqlFunc.AggregateMax(st.CreateTime),
                     sn = st.serial_number,
                     Frequency = SqlFunc.AggregateMax(st.freq),
-                    duration = (SqlFunc.AggregateMax(st.CreateTime) - SqlFunc.AggregateMin(st.CreateTime)).TotalSeconds,
+                    duration = (SqlFunc.AggregateMax(st.CreateTime) - SqlFunc.AggregateMin(st.CreateTime)).TotalSeconds == 0 ? 1 : (SqlFunc.AggregateMax(st.CreateTime) - SqlFunc.AggregateMin(st.CreateTime)).TotalSeconds,
                     model = st.device_type,
                     IsWhitelist = SqlFunc.AggregateMax(st.IsWhitelist)
                 }).OrderByDescending(s => s.batchId).ToListAsync();