about datasets

You use serialization: - manuallly (eg. DataSet.WriteXml method) - automatically while sending or getting data (eg. remoting, internet applications) See help "Introducing XML Serialization" in VS

thanks guys!But i have another question to raise. What's with serialization/deserialization? how important it is?

I usually don't. I have not run into too many problems using several datasets in one application. The only problem I ran into was when I was using a large dataset (over 5000 rows) and had to serialize it. If you don't know already DataSets do not serialize. I found that out the hard way. If your app does need to serialze or use larger dataset try using Arrays or ArrayLists of custom objects. Another solution may be to architect the app in way that only needs a few fields to show the basic information (like a list box only needs an ID, Value) and when a user selects it you do another query to get all the detail information. I try to use datasets as much as possible because they are easy to work with and like the fact that I am disconnected from the database. Geo http://www.EZDevComponents.com

Dataset was projected to do massive operations on many kinds of data, smart but not too quick. So, I try to use only one dataset in any of my objects, but: - if it is used as reference (address) - withot serialization/deserialization (1 .. 20 tables, 1 .. 500 fields, 2 .. 10000 records) - one datset in all the application - it's a mistake, if You have more then few tables or thousands of fields or records - use extended properties (strings) - they're smart instead of one-row-tables - split it into pieces if You use serialization/deserialization etc slow operations - if code should be fast - use simpler objects - remember about optimizing in all cases