Как сделать экспорт TDataSet в XML file?

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Code:

{Unit to export a dataset to XML}

 

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, '<?xml version="1.0" standalone="yes"?><!-- Generated by SMExport -->  ' +

   '<DATAPACKET Version="2.0">');

WriteString(Stream, '<METADATA><FIELDS>');

 

{write th metadata}

with Dataset do

   for i := 0 to FieldCount - 1 do

   begin

     WriteString(Stream, '<FIELD attrname="' +

       Fields[i].FieldName +

       '" fieldtype=' +

       XMLFieldType(Fields[i]) +

       '/>');

   end;

WriteString(Stream, '</FIELDS>');

WriteString(Stream, '<PARAMS DEFAULT_ORDER="1" PRIMARY_KEY="1" LCID="1033"/>');

WriteString(Stream, '</METADATA><ROWDATA>');

end;

 

procedure WriteFileEnd(Stream: TFileStream);

begin

WriteString(Stream, '</ROWDATA></DATAPACKET>');

end;

 

procedure WriteRowStart(Stream: TFileStream; IsAddedTitle: Boolean);

begin

if not IsAddedTitle then

   WriteString(Stream, '<ROW');

end;

 

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.

 

 

Code:

//Beispiel, Example:

 

 

uses DS2XML;

 

procedure TForm1.Button1Click(Sender: TObject);

begin DatasetToXML(Table1, 'test.xml');

end;

 

 

 

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