da.update(ds);
// da-->> object of dataAdapter
// da-->> object of Dataset

With use of following code we update the data set:-
 Using System.Data.SqlClient;
 Using System .Data;
 Using System.Configrution;
SqlDataAdpator da=new SqlDataAdaptor
("query",ConfigrutionSetting.AppSetting["key"]);
DataSet ds=new DataSet();
da.Fill(ds);
da.Update(ds);

usuing data.sqlclient;
---code----
sqldataadapter da=new dataadapter();
dataset ds=new dataset();
da.fill(ds);
da.update(ds)

or we cause to solve problem as--
public override int Update(
    DataSet dataSet
)