MysqlndUhConnection::getFieldCount

 MysqlndUhConnection::getFieldCount() is not only executed after the invocation of a user space API call which maps directly to it but also called internally. 
 
例1 MysqlndUhConnection::getFieldCount() example
 

class proxy extends MysqlndUhConnection {
 public function getFieldCount($res) {
   printf("%s(%s)\n", __METHOD__, var_export(func_get_args(), true));
   $ret = parent::getFieldCount($res);
   printf("%s returns %s\n", __METHOD__, var_export($ret, true));
   return $ret;
 }
}
mysqlnd_uh_set_connection_proxy(new proxy());

$mysqli = new mysqli("localhost", "root", "", "test");
$mysqli->query("WILL_I_EVER_LEARN_SQL?");
var_dump($mysqli->field_count);
$mysqli->query("SELECT 1, 2, 3 FROM DUAL");
var_dump($mysqli->field_count);

 
上の例の出力は以下となります。
 
proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 0
int(0)
proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 3
proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 3
int(3)