C#从access中读取出一些表写入到另一个Access

OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\\20101223-132821.mdb");
            conn.Open();
            OleDbDataAdapter emailAdapter = new OleDbDataAdapter(sql + "tab_BiaoZhuYangShi", conn);
            OleDbCommandBuilder cb = new OleDbCommandBuilder(emailAdapter);
            emailAdapter.Fill(ds, "tab_BiaoZhuYangShi");
            conn.Close();
            DataTable myDt = ds.Tables["tab_BiaoZhuYangShi"];
            myDt.PrimaryKey = new DataColumn[] { myDt.Columns["tab_BiaoZhuYangShi"] };
            //......//修改myDs数据
            emailAdapter.Update(ds, "tab_BiaoZhuYangShi");