BuddyPress.org

I’m trying to update a field in xprofile. This doesn’t seem to work:

$wpdb->query( $wpdb->prepare( "UPDATE {$wpdb->bp_xprofile_data} SET value = %s WHERE ID = %d AND field_id=1", $fullname, $user_id ) );

The $fullname is from elsewhere in my script.

Any suggestions how to fix this? Or is the problem somewhere else?