OledbDataAdapter 不更新表

我在更新数据表时遇到问题。 我正在做的是这样的：

1）从数据库加载数据（我们称之为"旧数据库"

2）从其他数据库加载数据（我们称之为"新数据库"）

3） 清除新数据库中的所有数据

4）将所有旧

数据（来自旧数据库）合并到新数据库中

以下是我尝试实现此目的的方法：

        string oldDatabase = this.txtOldReport.Text;
        string newDatabase = this.txtNewReport.Text;
        string backupFolder = @"C:'Planit'Report Updater'Backups";
        if ( !Directory.Exists ( backupFolder ) ) {
            Directory.CreateDirectory ( backupFolder );
        }
        string fullPath = Path.Combine ( backupFolder, string.Format ( @"Update Backup_{0}_{1}_{2}_{3}_{4}_{5}",
                                                                       DateTime.Now.Year,
                                                                       DateTime.Now.Month,
                                                                       DateTime.Now.Day,
                                                                       DateTime.Now.Hour,
                                                                       DateTime.Now.Minute,
                                                                       DateTime.Now.Second) );
        Directory.CreateDirectory ( fullPath );
        File.Copy ( oldDatabase, Path.Combine ( fullPath, @"Old Report.mdb" ) );
        File.Copy ( newDatabase, Path.Combine ( fullPath, @"New Report.mdb" ) );
        OleDbConnection oldConnection = new OleDbConnection ( string.Format ( @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", oldDatabase ) );
        OleDbConnection newConnection = new OleDbConnection ( string.Format ( @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0}", newDatabase ) );
        OleDbCommand oldCommand = oldConnection.CreateCommand ( );
        OleDbCommand newSelectCommand = newConnection.CreateCommand ( );
        oldCommand.CommandText = @"SELECT * FROM Reports";
        newSelectCommand.CommandText = @"SELECT * FROM Reports";
        oldConnection.Open ( );
        newConnection.Open ( );
        DataSet oldDataset = new DataSet ( );
        DataSet newDataset = new DataSet ( );
        OleDbDataAdapter oldAdapter = new OleDbDataAdapter ( oldCommand );
        OleDbDataAdapter newAdapter = new OleDbDataAdapter ( newSelectCommand );
        OleDbCommandBuilder builder = new OleDbCommandBuilder ( newAdapter );
        builder.QuotePrefix = "[";
        builder.QuoteSuffix = "]";
        newAdapter.UpdateCommand = builder.GetUpdateCommand ( true );
        newAdapter.InsertCommand = builder.GetInsertCommand ( true );
        newAdapter.DeleteCommand = builder.GetDeleteCommand ( true );
        oldAdapter.Fill ( oldDataset );
        newAdapter.Fill ( newDataset );
        newDataset.Tables [ 0 ].Rows.Clear ( );
        // removed for a response below
        //foreach ( DataRow dr in newDataset.Tables [ 0 ].Rows ) {
        //    dr.Delete ( );
        //}
        foreach ( DataRow dr in oldDataset.Tables [ 0 ].Rows ) {
            dr.SetAdded ( );
            newDataset.Tables [ 0 ].ImportRow ( dr );
        }
        // removed for the response below
        //newDataset.AcceptChanges ( );
        newAdapter.Update ( newDataset.Tables [ 0 ] );
        oldConnection.Close ( );
        newConnection.Close ( );
    }   

谁能看到我的问题？ 当我调用"newAdapter.Update"时，没有任何反应。

感谢您的任何帮助。

  newDataset.AcceptChanges ( );