下列代码不可以实现DBGrid的更新，请高手指教

Question

procedure TForm1.Button1Click(Sender: TObject);
begin
DBGrid1.Enabled:=true;
   query1.Close;
   query1.SQL.Clear;
   query1.SQL.Add('Insert into jifei values(:yonghu,:feiyong)');
   query1.ParamByname('yonghu').AsString:=Label3.Caption;
   query1.ParamByname('feiyong').AsString:=Edit1.Text;
   query1.ExecSQL;
   query1.Active:=false;
   query1.SQL.Clear;
   query1.SQL.Add('select yonghu,feiyong from jifei');
   query1.ExecSQL;
   query1.Close;
   query1.Open;
   query1.Active:=true;
end；

Answer 1

procedure TForm1.Button1Click(Sender: TObject);
begin
DBGrid1.Enabled:=true;
   query1.Close;
   query1.SQL.Clear;
   query1.SQL.Add('Insert into jifei values(:yonghu,:feiyong)');
   query1.ParamByname('yonghu').AsString:=Label3.Caption;
   query1.ParamByname('feiyong').AsString:=Edit1.Text;
   query1.ExecSQL;
   query1.Active:=false;
   query1.SQL.Clear;
   query1.SQL.Add('select yonghu,feiyong from jifei');
//   query1.ExecSQL;
//   query1.Close;
   query1.Open;
 //  query1.Active:=true;
end；

Answer 2

procedure TForm1.Button1Click(Sender: TObject);
begin
DBGrid1.Enabled:=true;
   query1.Close;
   query1.SQL.Clear;
   query1.SQL.Add('Insert into jifei values(:yonghu,:feiyong)');
   query1.ParamByname('yonghu').AsString:=Label3.Caption;
   query1.ParamByname('feiyong').AsString:=Edit1.Text;
   query1.ExecSQL;
   query1.Active:=false;
   query1.SQL.Clear;
   query1.SQL.Add('select yonghu,feiyong from jifei');
   //query1.ExecSQL;删除这句
   query1.open;
end；