php - store_result() and get_result() in mysql returns false -

i made code few days ago including get_result() receave results database. today wantet add , fix errors. tried use num_rows see if returned. had use store_result(). , when get_result() returns boolean of false. when comment out store_result() works should. know >= mess up. put = there debugging(to comment out store_result() , see happend). not problem

$sql = $this->connect(); $a = $sql->prepare("select `name`, `title`, `comment`, `date`  `comment` `post`=?"); $a->bind_param("s", $id); $a->execute(); $a->store_result(); if ($a->num_rows >= 0) {     $res = $a->get_result();     var_dump($res);      while ($row = $res->fetch_assoc()) {         $results[] = $row;     }     return $results; } else {     return false; } 

use get_result() instead of store_result(), , use result object's num_rows:

$a->execute(); $res = $a->get_result(); if ($res->num_rows > 0) {     while ($row = $res->fetch_assoc()) {         $results[] = $row;     }     return $results; } else {     return false; }