查询信息想在dbgrid中显示出来下面代码那错了?该如何解决

查询信息想在dbgrid中显示出来下面代码那错了???????
procedure TForm1.Button2Click(Sender: TObject);
begin
  if edit1.Text ='' then
  begin
  showmessage('请输入要查询的图书号!');
  exit;
  end;
  ado2.Close;
  ado2.SQL.Clear;
  ado2.SQL.add('select BookID from Book_Info where BookID='''+edit1.Text+'''');
  ado2.Open;
  if ado2.RecordCount <=0 then
  begin
  showmessage('该图书号不存在!');
  exit;
  end;
  try
  DBGrid1.Refresh;
  ado2.Close;
  ado2.SQL.Clear;
  ado2.SQL.add('Select from Book_Info where BookID='''+edit1.Text+'''');
  ado2.open;
  DBGrid1.Refresh;
  ado2.Close;
  ado2.SQL.Clear;
  ado2.SQL.add('Select from Book_Info where BookID='''+edit1.Text+'''');
  ado2.open;
  except
  showmessage('查询时出现错误,请核对数据是否正确!');
  end;
end;
procedure TForm1.Button3Click(Sender: TObject);
begin
close;
end;

end.


错误提示是SELECT语句问题或标点问题,或者是保留字问题.....

[解决办法]
BookID 是字符型字段吗，需要加引号吗
[解决办法]
如果是int类型的话就不需要那么多引号了 左右去掉2个
[解决办法]

Delphi(Pascal) code

......try  DBGrid1.Refresh;  ado2.Close;  ado2.SQL.Clear;  ado2.SQL.add('Select * from Book_Info where BookID='''+edit1.Text+'''');//原来没字段参数  ado2.open;  DBGrid1.Refresh;//为什么要重复下面的语句？//  ado2.Close;//  ado2.SQL.Clear;//  ado2.SQL.add('Select from Book_Info where BookID='''+edit1.Text+'''');//  ado2.open;except  showmessage('查询时出现错误,请核对数据是否正确!');end;......