SqlDependency.OnChange is not firing with filter on datetime column

Question

I am having issue using this SQL statement in SqlDependency. It simply not activating the SqlDependency.OnChange event, however returning the results as expected on SQL Server Query window.

SELECT [Order].OrderId
FROM [dbo].[Order]
WHERE [Order].CreatedOn > '20150815 21:11:57.502'

I read the Supported SELECT Statements section here https://technet.microsoft.com/en-us/library/ms181122(v=sql.105).aspx but didn't find any rule violated.

Any ideas?

Update:

My full code below:

    private void CheckForNewOrders(DateTime dt)
    {
        string json = null;
        string conStr = ConfigurationManager.ConnectionStrings["connstring"].ConnectionString;

        using (SqlConnection connection = new SqlConnection(conStr))
        {
            string query = string.Format(@"
                    SELECT [Order].OrderId
                    FROM [dbo].[Order]
                    WHERE [Order].CreatedOn > '{0}'"
, dt.ToString("yyyyMMdd HH:mm:ss.fff"));  // 20150814 00:00:00.000

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Notification = null;
                SqlDependency dependency = new SqlDependency(command);
                dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
                connection.Open();
                SqlDataReader reader = command.ExecuteReader();

                if (reader.HasRows)
                {
                    reader.Read();
                    json = "testing ... "; reader[0].ToString();
                }
            }
        }
    }

    private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
    {
        if (e.Type == SqlNotificationType.Change)
        {
            CheckForNewOrders(DateTime.Now);
        }
    }

Update (in response of jmelosegui's answer):

            query = string.Format(@"
                    SELECT [Order].OrderId
                    FROM [dbo].[Order]
                    WHERE [Order].CreatedOn > @CreatedOn");

...

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Parameters.Add("@CreatedOn", SqlDbType.DateTime);
                command.Parameters["@CreatedOn"].Value = DateTime.Now;

                command.Notification = null;
                SqlDependency dependency = new SqlDependency(command);
                dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
                connection.Open();
                SqlDataReader reader = command.ExecuteReader();

                if (reader.HasRows)
                {
                ...
                }
            }

Answer 1

I think you should be getting the notification event just not that type.

Could you add an else branch to your dependency_OnChange method to see if you are getting any other SqlNotificationType, such as:

private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
{
    if (e.Type == SqlNotificationType.Change)
    {
        CheckForNewOrders(DateTime.Now);
    }
    else
    {
        //Do somthing here
        Console.WriteLine(e.Type);
    }
}

Update

Could you try to add a typed parameter:

WHERE [Order].CreatedOn > @myDateTime

And pass in a parameter of type DateTime instead of using the string conversion.