如何使用 PHP 有效率地計算 MySQL 表中的行數？

$sql = "SELECT COUNT(*) FROM news";
$result = mysqli_query($con, $sql);
$count = mysqli_fetch_assoc($result)['COUNT(*)'];
echo $count;

$sql = "SELECT COUNT(*) as cnt FROM news";
$result = mysqli_query($con, $sql);
$count = mysqli_fetch_assoc($result)['cnt'];
echo $count;

$sql = "SELECT COUNT(*) FROM news";
$result = mysqli_query($con, $sql);
$count = mysqli_fetch_row($result)[0];
echo $count;

$sql = "SELECT COUNT(*) FROM news";
$result = mysqli_query($con, $sql);
$count = mysqli_fetch_column($result);
echo $count;

$sql = "SELECT COUNT(*) FROM news";
$count = $con->query($sql)->fetch_row()[0];
echo $count;

$sql = "SELECT COUNT(*) FROM news WHERE category=?";
$stmt = $con->prepare($sql);
$stmt->bind_param('s', $category);
$stmt->execute();
$count = $stmt->get_result()->fetch_row()[0];
echo $count;