TClientDataSet 如何更新服务器数据

Question

用了五个控件
1. HOST: TADOConnection
2. ADO: TADOQuery
3. DSP: TDataSetProvider
4. CDS: TClientDataSet
5. DS: TDataSource
6  DBGrid1: DBGrid;ADO.Connection := HOST;
DSP.DataSet := ADO;
CDS.ProviderName := DSP;
DS.DataSet := CDS;
DBGrid1.DataSource := DS;为什么我用CDS.ApplyUpdates(0);不能把已修改的数据提交到服务器呢？
我主要是想通过三层的方法更新数据，请各位大哥大姐指点下

Answer 1

你是做三层架构的，那你的服务端是怎么写的？你这里只是写了客户端的处理，TClientDataSet与服务端对应处理。再说你是用的Dcom还是Socket你好像哪 个也没有用！！

Answer 2

以前使用过的数据库操作类，你看看里面的UpdateDataSet方法，参数
SQLCommand:string;         --获得表结果
TableName:String;          --更新的表名
DataSet:TClientDataSet;    --需要更新的dataset
NotUpField:Array of string --不更新的字段名
调用
updatedataset('select * from tablename where 1=2','tablename',yourclientdataset,[]);
你看看是怎么实现的吧，要想直接用这个类，你简单修改一下也可以
unit IClsDBAccessADO;interfaceuses
  SysUtils, Classes, ADODB, Provider, DB, DBClient,Dialogs,Tool_N,IniFiles,IBase,MIDASLIB;
type
  TDBAccessADO = class (TDataModule, IDBAccess)
    ADOCommand1: TADOCommand;
    ADOConnection1: TADOConnection;
    ADODataSet1: TADODataSet;
    ClientDataSet1: TClientDataSet;
    DataSetProvider1: TDataSetProvider;
    procedure DataModuleCreate(Sender: TObject);
    procedure DataModuleDestroy(Sender: TObject);
    procedure DataSetProvider1BeforeUpdateRecord(Sender: TObject; SourceDS:
            TDataSet; DeltaDS: TCustomClientDataSet; UpdateKind: TUpdateKind;
            var Applied: Boolean);
  private
    FNotUpdateField: array of string;
    SqlPwd,SqlUserName,SqlDBName,ServerIp:string;
    //设置连接
    procedure SetConnectStr;
  public
    Function InitServer:integer;
    function ExecSQLCommand(SQLCommand:string): Integer; stdcall;
    function GetDataSet(SQLCommand:string;DataSet:TClientDataSet): Integer; 
            stdcall;
    function UpdateDataSet(SQLCommand:string;TableName:String; 
            DataSet:TClientDataSet;NotUpField:Array of string): Integer; 
            stdcall;
  end;
  
var
  DBAccessADO: TDBAccessADO;implementationuses FrmDialog;//uses SystemConst;{$R *.dfm}{ TDataModuleDBConMgr }{
********************************* TDBAccessADO *********************************
}procedure TDBAccessADO.DataModuleCreate(Sender: TObject);
var
  s: string;
begin
  s:='数据库连接失败！';
  if InitServer=S_False then exit;
end;procedure TDBAccessADO.DataModuleDestroy(Sender: TObject);
begin
  ADOConnection1.Connected:=False;
end;procedure TDBAccessADO.DataSetProvider1BeforeUpdateRecord(Sender: TObject;
        SourceDS: TDataSet; DeltaDS: TCustomClientDataSet; UpdateKind:
        TUpdateKind; var Applied: Boolean);
var
  int1: Integer;
  Field1: TField;
begin
  if Length(FNotUpdateField)=0 then Exit;
  for int1:=Low(FNotUpdateField) to High (FNotUpdateField) do
  begin
    Field1:=DeltaDS.FieldByName(FNotUpdateField[int1]);
    Field1.ProviderFlags:=
      Field1.ProviderFlags-[pfInUpdate,pfInWhere];
  end;
end;function TDBAccessADO.ExecSQLCommand(SQLCommand:string): Integer;
begin
  adocommand1.CommandText:=SqlCommand;
  try
    adoconnection1.Connected:=false;
    adoconnection1.Connected:=true;
    adocommand1.Execute;
    adoconnection1.Connected:=false;
    result:=S_OK;
  except
    result:=S_False;
  end;
end;function TDBAccessADO.GetDataSet(SQLCommand:string;DataSet:TClientDataSet):
        Integer;
begin
  try
    adoconnection1.Connected:=false;
    adoconnection1.Connected:=true;
    clientdataset1.Active:=false;
    clientdataset1.CommandText:=SQLCommand;
    clientdataset1.Active:=true;
    DataSet.Data:=ClientDataSet1.Data;
    clientdataset1.Active:=false;
    result:=S_OK;
  except
    result:=S_False;
  end;
end;function TDBAccessADO.InitServer: Integer;
//var
//  SQLPwd, SQLUserName, SQLDBName, ServerIP: string;  procedure InitSqlParam;
  var
    FileName:string;
  begin
    FileName:=GetMainPath+'resource\ServerList.ini';
    with TInifile.Create(Filename) do
    begin
      ServerIP:=ReadString('ServerInfo','ServerIP','');
      SQLDBName:=ReadString('ServerInfo','SQLDBName','');
      SQLUserName:=ReadString('ServerInfo','SQLUserID','');
      SQLPwd:=ReadString('ServerInfo','SQLPwd','');
      Destroy;
    end;
  end;begin
  InitSqlParam;  ADOConnection1.Connected:=False;
  ADOConnection1.ConnectionString:='Provider=SQLOLEDB.1;Password='+
    SQLPwd+
    ';Persist Security Info=True;'+
    'User ID='+
    SQLUserName+
    ';Initial Catalog='+
    SQLDBName+
    ';Data Source='+
    ServerIP;
  try
    ADOConnection1.Connected:=True;
    result:=S_OK;
  except
    result:=S_FALSE;
  end;end;procedure TDBAccessADO.SetConnectStr;
var
  ConnStr:string;
begin
  Connstr:='Provider=SQLOLEDB.1;Integrated Security=SSPI;'+
    'Persist Security Info=False;Data Source='+ServerIp;
  adoconnection1.Connected:=false;
  adoconnection1.ConnectionString:=ConnStr;
end;function TDBAccessADO.UpdateDataSet(SQLCommand:string;TableName:String;
        DataSet:TClientDataSet;NotUpField:Array of string): Integer;
var
  ErrorCount:integer;
  int1,int2:integer;
begin
  if DataSet=nil then
  begin
    result:=S_False;
    exit;
  end;
  if DataSet.ChangeCount=0 then
  begin
    result:=0;
    exit;
  end;
  try
    adoconnection1.Connected:=false;
    adoconnection1.Connected:=true;
  except
    result:=S_False;
    exit;
  end;  //FNotUpdateField
  int1:=length(NotUpField);
  if int1<>0 then
  begin
    setlength(FNotUpDateField,int1);
    int2:=0;
    for int1:=low(NotUpField) to high(notUpField) do
    begin
      FNotUpdateField[int2]:=NotUpField[int1];
      inc(int2);
    end;
  end;  try
    adodataset1.CommandText:=SQLCommand;
    clientDataset1.Data:=dataset.Delta;
    DataSetProvider1.ApplyUpdates(clientdataset1.Data,0,errorcount);
    if errorcount=0 then
      dataset.MergeChangeLog;
    result:=errorcount;
  except
    result:=S_False;
  end;
end;end.数据库配置文件ini内容
[ServerInfo]
ServerIP=127.0.0.1
SQLDBName=dngr
SQLUserID=sa
SQLPwd=sa

Answer 3

有三层代码的实例吗？我是用delphi 6/7的，如果可以的话，请发到我 邮箱里 [email protected]
不胜感激，这里的分不够，我重开再加