string connectionString = "Data Source=aspnet;User ID=aspnet;Password=aspnet;";

OracleConnection dbConnection = new OracleConnection(connectionString);

string selectString = "select * from Customers";

OracleDataAdapter dataAdapter = new OracleDataAdapter(selectString,dbConnection);

DataSet ds = new DataSet();

dbConnection.Open();

dataAdapter.Fill(ds,"Customers");

DataGrid1.DataSource = ds;

DataGrid1.DataBind();

OracleCommandBuilder cmdBuilder = new OracleCommandBuilder(dataAdapter);

ds.Tables["Customers"].Rows[0].Delete();

dataAdapter.Update(ds,"Customers");

DataGrid2.DataSource = ds;

DataGrid2.DataBind();
dbConnection.Close();

Error: Dynamic SQL generation for the DeleteCommand is not supported against a SelectCommand that does not return any key column information