unit UnitQuery;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, DBGrids, StdCtrls, DB, ADODB, StrUtils;

type
  TfrmQuery = class(TForm)
    GroupBox1: TGroupBox;
    dbg: TDBGrid;
    ds: TDataSource;
    qry: TADOQuery;
    GroupBox2: TGroupBox;
    memSQL: TMemo;
    btnExec: TButton;
    btnClose: TButton;
    procedure btnCloseClick(Sender: TObject);
    procedure btnExecClick(Sender: TObject);
    procedure memSQLChange(Sender: TObject);
    procedure FormShow(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmQuery: TfrmQuery;

implementation

uses UnitData;

{$R *.dfm}
// 執行關閉功能
procedure TfrmQuery.btnCloseClick(Sender: TObject);
begin
  Close;
end;
 // 通過按鈕“執行“完成查詢功能
procedure TfrmQuery.btnExecClick(Sender: TObject);
var
  str: string;
begin
//把前六個字符與“select”進行比較
  str := LeftStr(memSQL.Lines.Strings[0], 6);
  if CompareText(str, 'select') <> 0 then begin
    application.MessageBox(PAnsiChar('請使用select進行查詢！'), PAnsiChar('語句錯誤'), MB_OK + MB_ICONINFORMATION);
    //顯示消息框
    memSQL.Clear;
    btnExec.Enabled := FALSE;
    //“執行“按鈕無效
    exit;    
  end;
  qry.Close;
  qry.SQL := memSQL.Lines;
  qry.Open;
  //回顯查詢結果
  memSQL.Clear;
  btnExec.Enabled := FALSE;
end;

procedure TfrmQuery.memSQLChange(Sender: TObject);
begin
  btnExec.Enabled := memSQL.Lines.Count <> 0;
  // 如果輸入的字符行數不為0，“執行”按鈕有效
end;

procedure TfrmQuery.FormShow(Sender: TObject);
begin
  memSQL.SetFocus;
end;

end.