undefine lastInsertId()

[ngutip]

i've got error when
$query = $this->db->prepare($sales);
$query->execute();
$salesid = $query->lastInsertId();

Fatal error: Uncaught Error: Call to undefined method PDOStatement::lastInsertId() in ......

[ngutip]

my bad..
$salesid = $this->db->lastInsertId();