Как паковать базу данных?
Как паковать базу данных?
Using D6 Pro, Access XP and Jet 4.0 Sp6 - how can I compact Access files?
Answer:
This does it:
procedureTMainForm.ActionCompactAccessDBExecute(Sender: TObject);
var
JetEngine: Variant;
TempName: string;
aAccess: string;
stAccessDB: string;
SaveCursor: TCursor;
begin
stAccessDB := 'Provider = Microsoft.Jet.OLEDB.4.0;' +
'Data Source = %s;Jet OLEDB: Engine type = ';
stAccessDB := stAccessDB + '5'; {5 for Access 2000 and 4 for Access 97}
OpenDialog1.InitialDir := oSoftConfig.ApplicationPath + 'Data\';
OpenDialog1.Filter := 'MS Access (r) (*.mdb)|*.mdb';
if OpenDialog1.execute and (uppercase(ExtractFileExt
(OpenDialog1.FileName)) = '.MDB') then
begin
if MessageDlg('This process can take several minutes. Please wait till the end ' +
#13 + #10 + 'of it. Do you want to proceed? Press No to exit.', mtInformation,
[mbYes, mbNo], 0) = mrNo then
exit;
SaveCursor := screen.cursor;
screen.cursor := crHourGlass;
aAccess := OpenDialog1.FileName;
TempName := ChangeFileExt(aAccess, '.$$$');
DeleteFile(PChar(TempName));
JetEngine := CreateOleObject('JRO.JetEngine');
try
JetEngine.CompactDatabase(Format(stAccessDB, [aAccess]),
Format(stAccessDB, [TempName]));
DeleteFile(PChar(aAccess));
RenameFile(TempName, aAccess);
finally
JetEngine := Unassigned;
screen.cursor := SaveCursor;
end;
end;
end;
Important Notes:
1.1. Include the JRO_TLB unit in your uses clause.
2.2. Nobody should use or open the database during compacting.
3.3. If the compiler gives you an error on the JRO_TLB unit follow these steps:
·Using the Delphi IDE go to Project ? Import Type Library.
·Scroll down until you reach "Microsoft Jet and Replication Objects 2.1 Library".
·Click on Install button.
·Recompile a gain.
How to compact and repair MS Access 2000 (Jet Engine 4) during run time using Delphi 5?
Answer:
Usually the size of MS Access keep growing fast by time because of it's internal caching and temporary buffering, which in over whole effect the performance, space required for storing, and backing-up (if needed). The solution is to compact it from Access menus (Tools ? Database Utilities ? Compact and Repair Database) or to do that from inside your Delphi application.
function CompactAndRepair(sOldMDB: string; sNewMDB: string): Boolean;
const
sProvider = 'Provider=Microsoft.Jet.OLEDB.4.0;';
var
oJetEng: JetEngine;
begin
sOldMDB := sProvider + 'Data Source=' + sOldMDB;
sNewMDB := sProvider + 'Data Source=' + sNewMDB;
try
oJetEng := CoJetEngine.Create;
oJetEng.CompactDatabase(sOldMDB, sNewMDB);
oJetEng := nil;
Result := True;
except
oJetEng := nil;
Result := False;
end;
end;
Example :
if CompactAndRepair('e:\Old.mdb', 'e:\New.mdb') then
ShowMessage('Successfully')
else
ShowMessage('Error…');
Important Notes:
1.1. Include the JRO_TLB unit in your uses clause.
2.2. Nobody should use or open the database during compacting.
3.3. If the compiler gives you an error on the JRO_TLB unit follow these steps:
·Using the Delphi IDE go to Project ? Import Type Library.
·Scroll down until you reach "Microsoft Jet and Replication Objects 2.1 Library".
·Click on Install button.
·Recompile a gain.
Взято с
Delphi Knowledge Baseprocedure CompactDatabase_JRO(DatabaseName:string;DestDatabaseName:string='';Password:string='');
const
Provider = 'Provider=Microsoft.Jet.OLEDB.4.0;';
var
TempName : array[0..MAX_PATH] of Char; // имя временного файла
TempPath : string; // путь до него
Name : string;
Src,Dest : WideString;
V : Variant;
begin
try
Src := Provider + 'Data Source=' + DatabaseName;
if DestDatabaseName<>'' then
Name:=DestDatabaseName
else begin
// выходная база не указана - используем временный файл
// получаем путь для временного файла
TempPath:=ExtractFilePath(DatabaseName);
if TempPath='' Then TempPath:=GetCurrentDir;
//получаем имя временного файла
GetTempFileName(PChar(TempPath),'mdb',0,TempName);
Name:=StrPas(TempName);
end;
DeleteFile(PChar(Name));// этого файла не должно существовать :))
Dest := Provider + 'Data Source=' + Name;
if Password<>'' then begin
Src := Src + ';Jet OLEDB:Database Password=' + Password;
Dest := Dest + ';Jet OLEDB:Database Password=' + Password;
end;
V:=CreateOleObject('jro.JetEngine');
try
V.CompactDatabase(Src,Dest);// сжимаем
finally
V:=0;
end;
if DestDatabaseName='' then begin // т.к. выходная база не указана
DeleteFile(PChar(DatabaseName)); //то удаляем не упакованную базу
RenameFile(Name,DatabaseName); // и переименовываем упакованную базу
end;
except
// выдаем сообщение об исключительной ситуации
on E: Exception do ShowMessage(e.message);
end;
end;
Использование:
CompactDatabase_JRO('C:\MyDataBase\base.mdb','','123');
