a valid mysql query doesn't work in my script, why

hi mates,

i have a strange problem

i try to add a fonction in community builder component to display a kind of directory of registred users

and this code doesn't work and i don't know why

function show_annuaire() {
global $_CB_database;

$rubriqueid = intval( mosGetParam( $_GET, 'rubrique', 0 ));
$query = "SELECT * FROM #__comprofiler_field_values WHERE fieldvalueid = $rubriqueid";
$_CB_database->setQuery($query);
$dataObj = null;
$_CB_database->loadObject( $dataObj );

print_r($dataObj);
}

obviously, the query worked well in my phpmyadmin but not in my script

one day lost on this problem at this moment and i'm going a bit crazy

thanks for attention and help,
Patrick