Delphi开发系列（9）：修改客户端数据后更新到数据库

数据包装成JSon对象传到服务器端

procedure TForm1.Button2Click(Sender: TObject);
var
  data: string;
  strSQL: string;
  Delta: string;
  AStream: TStringStream;
  JSon: TJSonObject;
begin
  AStream := TStringStream.Create('', TEncoding.UTF8);
  JSon:= TJSonObject.Create;
  try
    RESTClient1.BaseURL := 'http://10.238.218.14:18022/datasnap/rest/TServerMethods1/DBTable/abc';
    RESTClient1.Authenticator := HTTPBasicAuthenticator1;

    if FDMemTable1.State in dsEditModes then
      FDMemTable1.Post;
    if FDMemTable1.ChangeCount = 0 then
      Exit;

    FDMemTable1.ResourceOptions.StoreItems := [siDelta, siMeta];
    FDMemTable1.SaveToStream(AStream, sfJSON);
    Delta := AStream.DataString;
    Memo1.Text := Delta;

    strSQL := 'select OrgCode,OrgName from MTS_Org where Upper(OrgEntry)=''ROOT''';
    JSon.AddPair('strSQL', strSQL);
    JSon.AddPair('DBAlias', 'ORACLE');
    JSon.AddPair('Delta',Delta);

    RESTRequest1.Method := TRESTRequestMethod.rmPost;
    RESTRequest1.Params.Clear;
    RESTRequest1.Body.ClearBody;
    RESTRequest1.AddBody(Format('{"data":"%s"}',[gFun.Encrypt(JSon.ToJSON,CONST_SM4_KEY)]), ctAPPLICATION_JSON);
    RESTRequest1.Execute;
  finally
    FDMemTable1.ResourceOptions.StoreItems := [siDelta, siMeta, siData];
    AStream.Free;
    JSon.Free;
  end;
end;

服务器端更新数据方法：

function TServerMethods1.updateDBTable(Value: string; Obj: TJSONObject): string;
var
  strSQL: string;
  DBAlias: string;
  strErrMsg : string;
  AStream: TStringStream;
  i : Integer;
  Json: TJSONObject;
  Delta: string;
  data: string;
begin
  if Obj<>nil then
    begin
      data := obj.GetValue('data').Value;
      data := gFun.Decrypt(data,CONST_SM4_KEY);
      Json := TJSONObject.ParseJSONValue(data) as TJSONObject;
      strSQL := Json.GetValue('strSQL').Value;
      DBAlias := Json.GetValue('DBAlias').Value;
      Delta := Json.GetValue('Delta').Value;
    end;
  if (DBAlias='')or(strSQL='')or(Delta='') then
    begin
      Result := '更新失败：没有接收到正确的更新数据！';
      Exit;
    end;
  FDConnection.ConnectionDefName := DBAlias;
  AStream := TStringStream.Create(Delta, TEncoding.UTF8);
  try
    try
      FDConnection.Connected := True;
      FDQuery.Connection := FDConnection;
      FDQuery.SQL.Text := strSQL;
      AStream := TStringStream.Create(Delta, TEncoding.UTF8);
      AStream.position := 0;
      FDQuery.LoadFromStream(AStream, sfJSON);
      FDQuery.ApplyUpdates(i);
    except
      on E: Exception do
      begin
        strErrMsg := 'TServerMethods1.EchoString: ' + E.Message;
      end;
    end;
  finally
    AStream.Free;
  end;
end;