masterquery.pas

《delphi数据库设计与实例开发》随书光盘

unit MasterQuery;

interface

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

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Splitter1: TSplitter;
    Panel2: TPanel;
    DBGrid1: TDBGrid;
    DBGrid2: TDBGrid;
    DataSource1: TDataSource;
    DataSource2: TDataSource;
    ADOQuery1: TADOQuery;
    ADOQuery2: TADOQuery;
    ADOConnection1: TADOConnection;
    procedure FormCreate(Sender: TObject);
    procedure ADOQuery1AfterOpen(DataSet: TDataSet);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
 CurDir:String;
begin
 GetDir(0,CurDir); //获得当前路径
 ADOConnection1.ConnectionString:='Provider=Microsoft.Jet.OLEDB.4.0;Data Source='+Curdir+'\DB\dbdemos.mdb;Persist Security Info=False';
 //建立连接字符串
 ADOConnection1.Connected:=True;//打开连接
 with ADOQuery1 do
 begin
  SQL.Clear;
  SQL.Add('select EmpNo,LastName,FirstName,PhoneExt,HireDate from employee');
  Open;
 end;


end;



procedure TForm1.ADOQuery1AfterOpen(DataSet: TDataSet);
begin
with ADOQuery2 do
  begin
   SQL.Clear;
   SQL.Add('select * from orders ');
   SQL.Add('where EmpNo=:NO');
   Parameters.ParamByName('NO').Value:=ADOQuery1.FieldbyName('EmpNo').asInteger;
   Close;
   Open;
   end;
end;

end.