即使记录中没有更改，SQL依赖项dependency_OnChange也会触发

Question

当SQL DB表中有更改时，我正在使用SQL依赖关系来更新dashoboard。 我在app_start（）事件中从Global.asax文件调用以下方法。

public void InitialiseMetricsDependency()
    {
        try
        {
            using (var connection = new SqlConnection(_connString))
            {

                if (connection.State == ConnectionState.Closed)
                    connection.Open();

                using (var command = new SqlCommand("SELECT [id],[Application],[customerName],[Actual] FROM [dbo].[Metrics]", connection))
                {
                    command.Notification = null;

                    dependency = new SqlDependency(command);
                    dependency.OnChange += dependency_OnChange;
                    if (connection.State == ConnectionState.Closed)
                        connection.Open();

                    var reader = command.ExecuteReader();
                }
            }
        }
        catch (Exception ex)
        {
            Log.Error(ex.InnerException.StackTrace);
        }
    }

现在我有以下dependency_OnChange事件

private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
    {
        try
        {
            if (e.Type == SqlNotificationType.Change)
            {
                using (var connection = new SqlConnection(_connString))
                {

                    if (connection.State == ConnectionState.Closed)
                        connection.Open();

                      using (var command = new SqlCommand("SELECT [id],[Application],[customerName],[Actual] FROM [dbo].[Metrics]", connection))
                    {
                        command.Notification = null;

                        dependency = new SqlDependency(command);

                        dependency.OnChange += dependency_OnChange;
                        if (connection.State == ConnectionState.Closed)
                            connection.Open();

                        var reader = command.ExecuteReader();

                    }
                }

               //push data to client
            }
        }
        catch (Exception ex)
        {
            Log.Error(ex.InnerException.StackTrace);
        }
    }

我正在通过其他API更新Metrics表，因此Api运行并更新Metircs表中的每一行。因此，on_change事件的每一行都会触发。 如果API值与现有行值相同，仍然依赖于dependency_OnChange事件

如果值真的发生变化，我怎样才能触发dependency_OnChange事件？