Delphi FireDAC 下的 Sqlite（十二） 備忘錄

該話題的繼續延伸主要就是 SQL 的語法了, 草草收場的原因是現在的腦筋已經進入了 IntraWeb 的世界.

相關備忘會隨時補充在下面:

//連接多個數據庫的參考代碼:
FDConnection1.ExecSQL('ATTACH ''c:hr.sdb'' AS hr');
FDConnection1.ExecSQL('ATTACH ''c:cust.sdb'' AS cust');
FDQuery1.Open('select * from "Orders" o ' +
  'left join hr."Employees" e on o.EmployeeID = e.EmployeeID ' +
  'left join cust."Customers" c on o.CustomerID = c.CustomerID');


//SQLite_OnAuthorize 參考代碼:procedure TForm1.FormCreate(Sender: TObject);
begin
  FDConnection1.Connected := True;
  TSQLiteDatabase(FDConnection1.ConnectionIntf.CliObj).OnAutorize := DoAuthorize;
  FDQuery1.Open;
end;

procedure TForm1.DoAuthorize(ADB: TSQLiteDatabase; ACode: Integer; const AArg1, AArg2, AArg3, AArg4: String; var AResult: Integer);
begin
  Memo1.Lines.Add(Format('%d - %s - %s - %s - %s', [ACode, AArg1, AArg2, AArg3, AArg4]));
  if ACode = SQLITE_DELETE thenAResult := SQLITE_DENY
  elseAResult := SQLITE_OK;
end;


//SQLite_OnUpdate 參考代碼:procedure TForm1.FormCreate(Sender: TObject);
begin
  FDConnection1.Connected := True;
  TSQLiteDatabase(FDConnection1.ConnectionIntf.CliObj).OnUpdate := DoUpdate;
  FDQuery1.Open;
end;

procedure TForm1.DoUpdate(ADB: TSQLiteDatabase; AOper: Integer; const ADatabase, ATable: String; ARowid: sqlite3_int64);
begin
  Memo1.Lines.Add(Format('%d - %s - %s - %u', [AOper, ADatabase, ATable, ARowid]));
end;


//快速選擇到行:
SELECT * FROM Orders WHERE ROWID = :RID

//TFDMemTable 代替 TClientDataSet
class="Delphi">procedure TForm1.FormCreate(Sender: TObject);
begin
  with FDMemTable1.FieldDefs.AddFieldDef do
  beginName := 'word';
    DataType := ftString;
    Size := 50;
  end;

  with FDMemTable1.FieldDefs.AddFieldDef do
  beginName := 'ph';
    DataType := ftString;
    Size := 50;
  end;

  with FDMemTable1.FieldDefs.AddFieldDef do
  beginName := 'note';
    DataType := ftString;
    Size := 255;
  end;

  with FDMemTable1.FieldDefs.AddFieldDef do
  beginName := 'num';
    DataType := ftInteger;
  end;

  FDMemTable1.IndexDefs.Add('Index_1', 'word', [ixPrimary]);
  FDMemTable1.CreateDataSet;
end;

//並發相關: http://docwiki.embarcadero.com/RADStudio/XE6/en/Using_SQLite_with_FireDAC#Locking_and_Concurrent_Updates

Author：cnblogs 萬一