Crlab公司用来连接MySQL数据库的控件

				unit Command;
				
				interface
				
				uses
				{$IFNDEF LINUX}
				  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
				  DBCtrls, ExtCtrls, Grids, DBGrids, StdCtrls, ToolWin, ComCtrls, MyDacVcl, Buttons,
				{$ELSE}
				  SysUtils, Types, Classes, QGraphics, QControls, QForms, QDialogs, QStdCtrls,
				  QButtons, QDBCtrls, QComCtrls, QExtCtrls, QGrids, QDBGrids,
				{$ENDIF}
				  Db, DAScript, DBAccess, MyAccess, DemoFrame, MyScript, MyDacDemoForm;
				
				type
				  TCommandFrame = class(TDemoFrame)
				    ToolBar: TPanel;
				    meSQL: TMemo;
				    Label1: TLabel;
				    Splitter1: TSplitter;
				    meResult: TMemo;
				    Panel1: TPanel;
				    btExecute: TSpeedButton;
				    MyCommand: TMyCommand;
				    btBreakExec: TSpeedButton;
				    btExecInThread: TSpeedButton;
				    procedure btExecuteClick(Sender: TObject);
				    procedure MySQLAfterExecute(Sender: TObject; Result: Boolean);
				    procedure btBreakExecClick(Sender: TObject);
				    procedure btExecInThreadClick(Sender: TObject);
				  private
				    { Private declarations }
				  public
				  // Demo management
				    procedure Initialize; override;
				    procedure SetDebug(Value: boolean); override;
				  end;
				
				  { TExecThread }
				
				  TExecThread = class(TThread)
				  protected
				    procedure Execute; override;
				    procedure Terminate;
				  end;
				
				var
				  CommandFrame: TCommandFrame;
				
				implementation
				
				{$IFDEF CLR}
				{$R *.nfm}
				{$ENDIF}
				{$IFDEF WIN32}
				{$R *.dfm}
				{$ENDIF}
				{$IFDEF LINUX}
				{$R *.xfm}
				{$ENDIF}
				
				procedure LogError(EMessage: string);
				begin
				  CommandFrame.meResult.Lines.Add('An error with the following message has beein raised during query execution:' + #13#10 + EMessage);
				end;
				
				{ TExecThread }
				
				procedure TExecThread.Execute;
				begin
				  if CommandFrame.MyCommand  nil then
				    try
				      CommandFrame.btBreakExec.Enabled := True;
				      CommandFrame.MyCommand.Execute;
				    except
				      on e: Exception do begin
				        LogError(e.Message);
				      end;
				    end;
				  Terminate;
				end;
				
				procedure TExecThread.Terminate;
				begin
				  inherited;
				  CommandFrame.btBreakExec.Enabled := False;
				end;
				
				{ TCommandFrame }
				
				procedure TCommandFrame.btExecuteClick(Sender: TObject);
				begin
				  MyCommand.SQL := meSQL.Lines;
				  MyDACForm.StatusBar.Panels[2].Text := 'Executing...';
				  meResult.Lines.Clear;
				  try
				    MyCommand.Execute;
				  except
				    on e: Exception do begin
				      LogError(e.Message);
				    end;
				  end;
				end;
				
				procedure TCommandFrame.btBreakExecClick(Sender: TObject);
				begin
				  MyCommand.BreakExec;
				end;
				
				procedure TCommandFrame.btExecInThreadClick(Sender: TObject);
				begin
				  MyCommand.SQL := meSQL.Lines;
				  MyDACForm.StatusBar.Panels[2].Text := 'Executing...';
				  meResult.Lines.Clear;
				  TExecThread.Create(False);
				end;
				
				procedure TCommandFrame.MySQLAfterExecute(Sender: TObject; Result: Boolean);
				var
				  s: string;
				begin
				  if Result then
				    s := 'Success' + '  (' + IntToStr(MyCommand.RowsAffected) + ' rows processed)'
				  else
				    s := 'Execution failed';
				  meResult.Lines.Add(s);
				  MyDACForm.StatusBar.Panels[2].Text := s;
				end;
				
				// Demo management
				procedure TCommandFrame.Initialize;
				begin
				  CommandFrame := self;
				  MyCommand.Connection := Connection as TCustomMyConnection;
				  MyCommand.SQL := meSQL.Lines;
				end;
				
				procedure TCommandFrame.SetDebug(Value: boolean);
				begin
				  MyCommand.Debug := Value;
				end;
				
				end.