adocommandemp.pas

《delphi数据库设计与实例开发》随书光盘

unit ADOCommandEmp;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    ADOCommand1: TADOCommand;
    DataSource1: TDataSource;
    Button2: TButton;
    DBGrid1: TDBGrid;
    ADOConnection1: TADOConnection;
    Button3: TButton;
    Button1: TButton;
    ADOQuery1: TADOQuery;
    procedure Button3Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button3Click(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
 Button1.Enabled:=true;
 Button3.Enabled:=False;
 with ADOQuery1 do
  begin
  SQL.Clear;
  SQL.Add('select * from employee');
  Open;
  end;
 showmessage('连接成功！');
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
with ADOCommand1 do
 begin
  CommandType:=cmdText;
  CommandText:='Update employee set Salary=Salary*:Rate';
  Parameters.ParamByName('Rate').Value:=1+StrToInt(trim(edit1.Text))/100;
  Execute;
 end;
 Button2.Enabled:=True;
 showmessage('更新成功！');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
 with ADOQuery1 do
  begin
  SQL.Clear;
  SQL.Add('Select * from employee');
  open;
  end;
end;

end.