Delphi 带有 MS Access 2010 数据库的 FireDAC。为什么它将 ACE 转换为 Jet?

Delphi FireDAC with MS Access 2010 database. Why does it convert ACE to Jet?

我已按照以下步骤将 .mdb 数据库转换为 .accdb 数据库: https://support.office.com/en-us/article/Convert-a-database-to-the-accdb-file-format-69abbf06-8401-4cf3-b950-f790fa9f359c (使用 MS Access 2010)

转换后,.accdb 文件以以下内容开头: (database.accdb,使用十六进制编辑器查看文件头),这正是我想要的...

00 01 00 00 53 74 61 6E 64 61 72 64 20 41 43 45 20 44 42 00 02 00 00 00 B5 6E 03 62 60 09 C2 55 E9 A9 67 72 40 3F 00 9C 7E 9F 90 FF 85 9A 31 C5
....Standard ACE DB.....µn.b`.ÂUé©gr@?.œ~Ÿ.ÿ…š1Å

打开数据库后,删除 table,重新创建 table 并使用 TFDConnection / TFDPhysMSAccessDriverLink / TFDBatchMove / TFDBatchMoveDataSetReader / TFDBatchMoveDataSetWriter 和以下代码进行一些插入

  FAccessDB := TFDConnection.Create(Self);
  FAccessDB.Name := '';
  FAccessDB.Params.Clear;
  FAccessDB.Params.Add('DriverID=MSAcc_Direct');
  FAccessDB.LoginPrompt := False;

  // FDPhysMSAccessDriverLink1
  FFDPhysMSAccessDriverLink1 := TFDPhysMSAccessDriverLink.Create(Self);
  FFDPhysMSAccessDriverLink1.Name := '';
  FFDPhysMSAccessDriverLink1.DriverID := 'MSAcc_Direct';

  // Table_Out
  FFDTable_Out := TFDTable.Create(Self);
  FFDTable_Out.Name := '';
  FFDTable_Out.Connection := FAccessDB;

  // FDBatchMove1
  FFDBatchMove1 := TFDBatchMove.Create(Self);
  FFDBatchMove1.Name := '';
  FFDBatchMove1.OnError := FDBatchMove1Error;
  FFDBatchMove1.OnFindDestRecord := FDBatchMove1FindDestRecord;
  FFDBatchMove1.OnProgress := FDBatchMove1Progress;

  // FDBatchMoveDataSetReader1
  FFDBatchMoveDataSetReader1 := TFDBatchMoveDataSetReader.Create(Self);
  FFDBatchMoveDataSetReader1.Name := '';

  // FDBatchMoveDataSetWriter1
  FFDBatchMoveDataSetWriter1 := TFDBatchMoveDataSetWriter.Create(Self);
  FFDBatchMoveDataSetWriter1.Name := '';

  // FDBatchMove1
  FFDBatchMove1.Reader := FFDBatchMoveDataSetReader1;
  FFDBatchMove1.Writer := FFDBatchMoveDataSetWriter1;
  FFDBatchMove1.Options := [poIdentityInsert];

  FAccessDB.Params.Values['Database'] := 'database.accdb';
  FAccessDB.Connected := True;
  aDropTableSQL := 'DROP TABLE ' + FTablenameDest;
  FAccessDB.ExecSQL(aDropTableSQL);
  FAccessDB.Commit;
  aCreateTableSQL := 'CREATE TABLE ' + FTablenameDest; // plus the rest 
                                              //of the create statement

  FFDTable_Out.TableName := FTablenameDest;
  FFDTable_Out.Active := True;
  FFDBatchMoveDataSetReader1.DataSet := FDataSetSrc; // a TDataset from 
                                                       // another database 
  FFDBatchMoveDataSetWriter1.DataSet := FFDTable_Out;
  FFDBatchMoveDataSetWriter1.Direct := True;

  FFDBatchMoveDataSetReader1.DataSet.Active := True;
  FFDBatchMoveDataSetWriter1.DataSet.Active := True;

  FFDBatchMove1.Mode := dmAlwaysInsert;
  FFDBatchMove1.Execute;
  FAccessDB.Commit;
  FAccessDB.Connected := False;

  FFDMSAccessService1 := TFDMSAccessService.Create(Self);
  FFDMSAccessService1.Name := '';

  FFDMSAccessService1.Database := 'database.accdb';
  FFDMSAccessService1.DestDatabase := 'database.accdb_temp.accdb';

  FFDMSAccessService1.DBVersion := avAccess2007;

  FFDMSAccessService1.Compact;   // <-- seems to convert here...

database.accdb的文件头变为

00 01 00 00 53 74 61 6E 64 61 72 64 20 4A 65 74 20 44 42 00 01 00 00 00 B5 6E 03 62 60 09 C2 55 E9 A9 67 72 40 3F 00 9C 7E 9F 90 FF 85 9A 31 C5
....Standard Jet DB.....µn.b`.ÂUé©gr@?.œ~Ÿ.ÿ…š1Å

同样,在从 .mdb 转换为 .accdb 之前也是如此

在我看来,'Standard Jet DB' 表示旧格式 (.mdb) 'Standard ACE DB' 表示新格式 (.accdb)

FireDAC 会把它转换回来吗?为什么? 如何保留新的访问格式(.accdb、ACE DB)?

刚刚收到 Embarcadero 的答复(非常快的答复,酷!):

Dmitry Arefiev 写道: 这是一个已知的问题。目前 TFDMSAccessService 并不真正支持 avAccess2007。

--

谨致问候, Dmitry Arefiev / FireDAC 架构师