Create a XML-file with data from some dataset (Views: 27)
Problem/Question/Abstract: How to generate the XML-file from linked dataset? Answer: Solve 1: Sometimes in our development we must export a data from dataset into different formats like MS Excel, Word, HTML, Text etc. Now in the Internet we have a new popular format - XML-file. So for large part of applications we wants to include the possibility of export into XML, of course. I want to demonstrate the sample of one procedure for exporting of dataset's data into XML: procedure DatasetToXML(Dataset: TDataset; FileName: string); The first Dataset parameter is source dataset with data (your Table or Query component, or some other third-party dataset). The second FileName parameter is a name of target XML-file. { SMExport suite's free demo Data export from dataset into XML-file Copyright(C) 2000, written by Scalabium, Shkolnik Mike E-Mail: smexport@scalabium.com mshkolnik@yahoo.com WEB: http://www.scalabium.com http://www.geocities.com/mshkolnik } unit DS2XML; interface uses Classes, DB; procedure DatasetToXML(Dataset: TDataset; FileName: string); implementation uses SysUtils; var SourceBuffer: PChar; procedure WriteString(Stream: TFileStream; s: string); begin StrPCopy(SourceBuffer, s); Stream.Write(SourceBuffer[0], StrLen(SourceBuffer)); end; procedure WriteFileBegin(Stream: TFileStream; Dataset: TDataset); function XMLFieldType(fld: TField): string; begin case fld.DataType of ftString: Result := '"string" WIDTH="' + IntToStr(fld.Size) + '"'; ftSmallint: Result := '"i4"'; //?? ftInteger: Result := '"i4"'; ftWord: Result := '"i4"'; //?? ftBoolean: Result := '"boolean"'; ftAutoInc: Result := '"i4" SUBTYPE="Autoinc"'; ftFloat: Result := '"r8"'; ftCurrency: Result := '"r8" SUBTYPE="Money"'; ftBCD: Result := '"r8"'; //?? ftDate: Result := '"date"'; ftTime: Result := '"time"'; //?? ftDateTime: Result := '"datetime"'; else end; if fld.Required then Result := Result + ' required="true"'; if fld.Readonly then Result := Result + ' readonly="true"'; end; var i: Integer; begin WriteString(Stream, ' ' + ' WriteString(Stream, ' {write th metadata} with Dataset do for i := 0 to FieldCount - 1 do begin WriteString(Stream, ' end; WriteString(Stream, ' WriteString(Stream, ' WriteString(Stream, ' end; procedure WriteFileEnd(Stream: TFileStream); begin WriteString(Stream, ' end; procedure WriteRowStart(Stream: TFileStream; IsAddedTitle: Boolean); begin if not IsAddedTitle then WriteString(Stream, ' procedure WriteRowEnd(Stream: TFileStream; IsAddedTitle: Boolean); begin if not IsAddedTitle then WriteString(Stream, '/>'); end; procedure WriteData(Stream: TFileStream; fld: TField; AString: ShortString); begin if Assigned(fld) and (AString <> '') then WriteString(Stream, ' ' + fld.FieldName + '="' + AString + '"'); end; function GetFieldStr(Field: TField): string; function GetDig(i, j: Word): string; begin Result := IntToStr(i); while (Length(Result) < j) do Result := '0' + Result; end; var Hour, Min, Sec, MSec: Word; begin case Field.DataType of ftBoolean: Result := UpperCase(Field.AsString); ftDate: Result := FormatDateTime('yyyymmdd', Field.AsDateTime); ftTime: Result := FormatDateTime('hhnnss', Field.AsDateTime); ftDateTime: begin Result := FormatDateTime('yyyymmdd', Field.AsDateTime); DecodeTime(Field.AsDateTime, Hour, Min, Sec, MSec); if (Hour <> 0) or (Min <> 0) or (Sec <> 0) or (MSec <> 0) then Result := Result + 'T' + GetDig(Hour, 2) + ':' + GetDig(Min, 2) + ':' + GetDig(Sec, 2) + GetDig(MSec, 3); end; else Result := Field.AsString; end; end; procedure DatasetToXML(Dataset: TDataset; FileName: string); var Stream: TFileStream; bkmark: TBookmark; i: Integer; begin Stream := TFileStream.Create(FileName, fmCreate); SourceBuffer := StrAlloc(1024); WriteFileBegin(Stream, Dataset); with DataSet do begin DisableControls; bkmark := GetBookmark; First; {write a title row} WriteRowStart(Stream, True); for i := 0 to FieldCount - 1 do WriteData(Stream, nil, Fields[i].DisplayLabel); {write the end of row} WriteRowEnd(Stream, True); while (not EOF) do begin WriteRowStart(Stream, False); for i := 0 to FieldCount - 1 do WriteData(Stream, Fields[i], GetFieldStr(Fields[i])); {write the end of row} WriteRowEnd(Stream, False); Next; end; GotoBookmark(bkmark); EnableControls; end; WriteFileEnd(Stream); Stream.Free; StrDispose(SourceBuffer); end; end. Solve 2: there is a simpler way of saving the resultset in a xml-file... drop a TClientDataSet and a TdataSetProvider on the form. set the TDatasetProvider.dataset to point to your TQuery. Set the TClientDataSet.ProviderName to point to the TDataSetProvider. In the code write: ClientDataSet.active := true; ClentDataSet.SaveToFile('c: \results.xml'); as long as the type name of the file is xml, it will be a xml-file. |