How update?

Hi! I have problem. I can select database, but I can't update. I generate : string query = "update asia set nowa = 'lala' where nowa='qqq'" ; string strCon = @"Provider=MSDAORA.1;Password=aaa;User ID=bbb;Data Source=test"; try { OleDbConnection myCon= new OleDbConnection(strCon); OleDbDataAdapter myAda = new OleDbDataAdapter(); myAda.UpdateCommand = new OleDbCommand (query,myCon); myAda.Fill(myDataSet1,"X"); dataGrid1.DataSource = myDataSet1; } catch { MessageBox.Show("There was some error", "DB Error", MessageBoxButtons.OK, MessageBoxIcon.Error) ; } What is bad? Help me.