oracleDataAdapter.UpdateCommand = new Oracle.DataAccess.Client.OracleCommand("UPDATE EMP SET ENAME=:ENAME WHERE EMPNO=:EMPNO", oracleConnection);

oracleDataAdapter.UpdateCommand.Parameters.Add(new OracleParameter("EMPNO", OracleDbType.Int16, 10, "EMPNO"));
oracleDataAdapter.UpdateCommand.Parameters.Add(new OracleParameter("ENAME", OracleDbType.Varchar2, 30, "ENAME"));

oracleDataAdapter.Update(dataSet);