那位高手能解决，编译没有错误，却不显示数据

procedure TForm1.Button1Click(Sender: TObject);
begin
       qrysel:=TADOQuery.Create(nil);
        try
            qrysel.ConnectionString   :='Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=test_ccerp;Data Source=192.168.16.229;';   //设置连接串

              //qrysel.ConnectionString := TADOConnection;

            with   qrysel        do
            begin

            qrysel.Active:=false;
               qrysel.close;
                qrysel.sql.clear;
               qrysel.sql.add('select * from   bmdoc');


                try
                 qrysel.Open;
                 //qrysel.execsql;
                 //qrysel.Next;

                     DataSource1.DataSet:=qrysel;
                    DBGrid1.DataSource:=DataSource1;
                    DBGrid1.Align := alClient;
                       qrysel.Active:=True;

                except
                    showmessage('error');
                end;


            end;

        finally
            qrysel.free;
        end;
end;