identified datatable row is empty in data set

how to identified when row is empty when data set is used
Not too clear but all it makes sense if you want to know that if dataset table has any data. If so, you can use Rows count.

if(myDataset.Tables[0].Rows.Count > 0)
{
  // there is some data.
}

Having an empty row in a table does not makes sense as if no value is there, it would not be a part of table at all when you retrieved it.