简化：mysqli的NUM_ROWS不工作(simplified: mysqli num_rows

我如何使用输出返回mysqli的行数？ 下面我的代码示出了0虽然while循环（而$ S->取（）回声$ UID;）示出了2点的结果;

$m = new mysqli(MYSQL_SERVER, MYSQL_USER, MYSQL_PASS, MYSQL_DB);
$s=$m->prepare("SELECT uid FROM user WHERE token=? AND secret=?");
$s->bind_param('ss',$rt, $rs);
$rt='c';
$rs='d';
$s->execute();
$s->bind_result($uid);
$s->fetch();
print_r($s->num_rows); // RESULTS IN 0

Answer 1:

你必须调用mysqli_stmt::store_result()后mysqli_stmt::execute()并获取以了解前mysqli_stmt::num_rows ：

$s->execute();
$s->store_result();
print_r($s->num_rows);

在PHP文件num_rows

PHP文件上store_result()

文章来源: simplified: mysqli num_rows not working