判断数据库时时连接程序，判断是否断开，断开则自动连接

try
    with    ADOQuery_temp   do
    begin
            Close;
            SQL.Clear;
            SQL.Add('select top 1 id from y_users ');
            Open;
    end;
except
    Frm_Data.ADOConnection1.Connected:=False;
    Frm_Data.ADOConnection1.Connected:=True;
end;