How to add graphics asynchronously from a database in real time

[hcgis]

hi all
i want to plot points in my map every each period of time. these points are stored in sql server database
how can i do this
i m waiting for your suggestions

[derekswingley1]

Are you using ArcGIS Server to serve your data?

[hcgis]

Hi Derek
we have an AVL database (SQL Server) and i want to add vehicle loctions to the map every selected period of time (1min, 2min...).
i'm just asking how to add and  refresh these positions asynchronously without a full refresh of the map.
I want also to trace a vehicle by zooming to its position, the update on the map should be auto refresh at a prerdefined set time,
and draw the line of the path
I m using ArcGIS Server to serve other spatial data

[JianHuang]

Those points could be added to graphicsLayer. When you need to refresh the layer, you can simply remove all existing graphics by calling graphicsLayer.clear(), and then add the current graphics to it.