Mega Code Archive
How to export a TDBGrid to excel without OLE
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Title: How to export a TDBGrid to excel without OLE
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.
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