num_rows not work on object

[eluser]RJ[/eluser]

Code:

$query = $TT->query("SELECT devicetype, TO_CHAR(subversion) FROM ttdevice WHERE msisdn = '".$this->MSISDN."' AND unitid = '".$this->UNITID."'");

This is the query; if you leave out the num_rows check and dump $rows you get:

stdClass Object ( [DEVICETYPE] => 1 [TO_CHAR(SUBVERSION)] => 0 )

NUM_ROWS produces a result of -1. So based on the foreach in the beginning of this post, I can not have a check on $query. I think num_rows doesn't work because its not a row, i'm getting back objects; but the user guide said the num_rows check should work... and doesn't.

Does that makes sense?