export from gbGrid to Excel

[juna23]

I need to export from gbGrid to Excel (.xls). Th dbGrid contains alot of records.
The export should generate an excel file upon button click.
Can anyone help with the code?

Thanks,
Juna

 

[sggaunt]

Have a look at the FAQ section I think there are some hints on how to do this.

Steve [The sane]: Delphi a feersum engin indeed.

 

[juna23]

Thank you for your suggestion.

I have tried several exports but the problems comes up when I need to export large number of rows like 40000 or more,
I get an OLE error message.
Can you help me overcome this problem.


Juna

 

[DelphiAaron]

have you tried any of the vcl's at

http://www.torry.net

?

Aaron

 

[juna23]

No I haven't. is there any that can help?

Juna

 

[whosrdaddy]

Save following code as a unit,
follow instructions a stated:

{
  Exporting a DBGrid to excel without OLE

  First of all you must import the ADOX type library
  which will be used to create the Excel file and its
  internal structure: in the Delphi IDE:

  1)Project->Import Type Library:
  2)Select "Microsoft ADO Ext. for DDL and Security"
  3)Uncheck "Generate component wrapper" at the bottom
  4)Rename the class names (TTable, TColumn, TIndex, TKey, TGroup, TUser, TCatalog) in
    (TXTable, TXColumn, TXIndex, TXKey, TXGroup, TXUser, TXCatalog)
    in order to avoid conflicts with the already present TTable component.
  5)Select the Unit dir name and press "Create Unit".
    It will be created a file named AOX_TLB.
    Include ADOX_TLB in the "uses" directive inside the file in which you want
    to use ADOX functionality.

  That is all. Let's go now with the implementation:
}

unit DBGridExportToExcel;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, StdCtrls, ComCtrls, DB, IniFiles, Buttons, dbgrids, ADOX_TLB, ADODB;


type TScrollEvents = class
       BeforeScroll_Event: TDataSetNotifyEvent;
       AfterScroll_Event: TDataSetNotifyEvent;
       AutoCalcFields_Property: Boolean;
  end;

procedure DisableDependencies(DataSet: TDataSet; var ScrollEvents: TScrollEvents);
procedure EnableDependencies(DataSet: TDataSet; ScrollEvents: TScrollEvents);
procedure DBGridToExcelADO(DBGrid: TDBGrid; FileName: string; SheetName: string);


implementation

//Support procedures: I made that in order to increase speed in
//the process of scanning large amounts
//of records in a dataset

//we make a call to the "DisableControls" procedure and then disable the "BeforeScroll" and
//"AfterScroll" events and the "AutoCalcFields" property.
procedure DisableDependencies(DataSet: TDataSet; var ScrollEvents: TScrollEvents);
begin
     with DataSet do
          begin
               DisableControls;
               ScrollEvents := TScrollEvents.Create();
               with ScrollEvents do
                    begin
                         BeforeScroll_Event := BeforeScroll;
                         AfterScroll_Event := AfterScroll;
                         AutoCalcFields_Property := AutoCalcFields;
                         BeforeScroll := nil;
                         AfterScroll := nil;
                         AutoCalcFields := False;
                    end;
          end;
end;

//we make a call to the "EnableControls" procedure and then restore
// the "BeforeScroll" and "AfterScroll" events and the "AutoCalcFields" property.
procedure EnableDependencies(DataSet: TDataSet; ScrollEvents: TScrollEvents);
begin
     with DataSet do
          begin
               EnableControls;
               with ScrollEvents do
                    begin
                         BeforeScroll := BeforeScroll_Event;
                         AfterScroll := AfterScroll_Event;
                         AutoCalcFields := AutoCalcFields_Property;
                    end;
          end;
end;

//This is the procedure which make the work:

procedure DBGridToExcelADO(DBGrid: TDBGrid; FileName: string; SheetName: string);
var
  cat: _Catalog;
  tbl: _Table;
  col: _Column;
  i: integer;
  ADOConnection: TADOConnection;
  ADOQuery: TADOQuery;
  ScrollEvents: TScrollEvents;
  SavePlace: TBookmark;
begin
  //
  //WorkBook creation (database)
  cat := CoCatalog.Create;
  cat.Set_ActiveConnection('Provider=Microsoft.Jet.OLEDB.4.0; Data Source=' + FileName + ';Extended Properties=Excel 8.0');
  //WorkSheet creation (table)
  tbl := CoTable.Create;
  tbl.Set_Name(SheetName);
  //Columns creation (fields)
  DBGrid.DataSource.DataSet.First;
  with DBGrid.Columns do
    begin
      for i := 0 to Count - 1 do
        if Items[i].Visible then
        begin
          col := nil;
          col := CoColumn.Create;
          with col do
            begin
              Set_Name(Items[i].Title.Caption);
              Set_Type_(adVarWChar);
            end;
          //add column to table
          tbl.Columns.Append(col, adVarWChar, 20);
        end;
    end;
  //add table to database
  cat.Tables.Append(tbl);

  col := nil;
  tbl := nil;
  cat := nil;

  //exporting
  ADOConnection := TADOConnection.Create(nil);
  ADOConnection.LoginPrompt := False;
  ADOConnection.ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0; Data Source=' + FileName + ';Extended Properties=Excel 8.0';
  ADOQuery := TADOQuery.Create(nil);
  ADOQuery.Connection := ADOConnection;
  ADOQuery.SQL.Text := 'Select * from [' + SheetName + '$]';
  ADOQuery.Open;


  DisableDependencies(DBGrid.DataSource.DataSet, ScrollEvents);
  SavePlace := DBGrid.DataSource.DataSet.GetBookmark;
  try
  with DBGrid.DataSource.DataSet do
    begin
      First;
      while not Eof do
        begin
          ADOQuery.Append;
          with DBGrid.Columns do
            begin
              ADOQuery.Edit;
              for i := 0 to Count - 1 do
                if Items[i].Visible then
                  begin
                    ADOQuery.FieldByName(Items[i].Title.Caption).AsString := FieldByName(Items[i].FieldName).AsString;
                  end;
              ADOQuery.Post;
            end;
          Next;
        end;
    end;

  finally
  DBGrid.DataSource.DataSet.GotoBookmark(SavePlace);
  DBGrid.DataSource.DataSet.FreeBookmark(SavePlace);
  EnableDependencies(DBGrid.DataSource.DataSet, ScrollEvents);

  ADOQuery.Close;
  ADOConnection.Close;

  ADOQuery.Free;
  ADOConnection.Free;

  end;

end;

end.

-----------------------------------------------------
What You See Is What You Get
Never underestimate tha powah of tha google!

 

[juna23]

I have tried several solution ant they work fine( although a bit slow) BUT when in comes to exporting more then 65536 records( close to excel limit) I encounter errors.

Juna