// Be sure we are not trying to add a non existing user to the conversation. Work only with existing users.
list($useridcondition, $params) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED);
- $existingusers = array_keys($DB->get_records_select_menu('user',
- "id $useridcondition", $params, 'id', 'id, id'));
+ $existingusers = $DB->get_fieldset_select('user', 'id', "id $useridcondition", $params);
// Be sure we are not adding a user is already member of the conversation. Take all the members.
$memberuserids = array_values($DB->get_records_menu(