OleDbCommand更新数据的一些问题

using (OleDbConnection connection1 = new OleDbConnection(connectionString))
{
OleDbCommand command1 = new OleDbCommand();
command1.Connection = connection1;
command1.CommandType = CommandType.Text;
command1.CommandText = "select * from 成绩单";
connection1.Open();//打开连接
OleDbDataAdapter myDataAdapter1 = new OleDbDataAdapter(command1);
myDataAdapter1.SelectCommand = command1;
DataSet ds = new DataSet();
myDataAdapter1.Fill(ds,"成绩单");
command1.CommandText = "UPDATE 成绩单 SET ASP=" + finalMarks + " WHERE 学号=" + Application["user"];
OleDbDataAdapter myDataAdapter2 = new OleDbDataAdapter();
myDataAdapter2.UpdateCommand = command1;
command1.ExecuteNonQuery();
try { }
catch { };
myDataAdapter2.Update(ds,"成绩单");

}