unit441.pas

Delphi6分布式开发例程12 )

unit Unit441;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Db, DBClient, MConnect, MidasCon,Variants;

type
  TDM = class(TDataModule)
    ClientDataSet1: TClientDataSet;
    DataSource1: TDataSource;
    DCOMConnection1: TDCOMConnection;
    ClientDataSet1CustNo: TFloatField;
    ClientDataSet1Company: TStringField;
    ClientDataSet1Addr1: TStringField;
    ClientDataSet1Addr2: TStringField;
    ClientDataSet1City: TStringField;
    ClientDataSet1State: TStringField;
    ClientDataSet1Zip: TStringField;
    ClientDataSet1Country: TStringField;
    ClientDataSet1Phone: TStringField;
    ClientDataSet1FAX: TStringField;
    ClientDataSet1TaxRate: TFloatField;
    ClientDataSet1Contact: TStringField;
    ClientDataSet1LastInvoiceDate: TDateTimeField;
  private
    { Private declarations }
  public
    procedure ApplyUpdates;
    { Public declarations }
  end;

var
  DM: TDM;

implementation

{$R *.DFM}
procedure TDM.ApplyUpdates;
var
  CustVar: OleVariant;
begin
 // 这行程序用来检查用户最后修改或添加的数据
  // 是否已经Post到DataSet，如果没有，则自动执行
  // Post命令，确保用户所改的数据写入DataSet。

  ClientDataSet1.CheckBrowseMode;

  // 判断DataSet是否变动，如果有，则把变动的那
  // 几条数据指定给CustVar变量，如果没有，则把CustVar
  // 变量设成non
  if ClientDataSet1.ChangeCount > 0 then
     CustVar := ClientDataSet1.Delta
  else CustVar := NULL;
  // 把存放变动数据记录的变量CustVar，通过应用程序服务器所
  // 提供的Interface method传给应用程序服务器，最后再写回
  // 后台的数据库内。

  try
    DCOMConnection1.AppServer.ApplyUpdates(CustVar);
    ShowMessage('写入数据库成功!');
  except
    ShowMessage('写入数据库失败!');
  end;
end;

end.