无法在mysqli中使用方法链接

Question

代码看起来很简单

$q = "SELECT COUNT(*) as 'total' FROM table";


// does not work
$total = $conn->query($q)->fetch_assoc()['total']; 



// works
$res1 = $conn->query($qcount_no_admin);
$row1 = $res1->fetch_assoc();
$total = $row1['total'];

我收到500错误（暂时我无法显示错误，必须与主持人交谈）。

这种方法链接在php mysqli中是否可行？