使用 PHP 计算 MySQL 数据库中的行数

Question

你们能帮我处理这段代码吗？我想在我的评论表中计算向下的数量，但我似乎不起作用。

$count_result =  mysqli_query($con, 'SELECT COUNT(*) FROM comments WHERE id=$get_id');

Answer 1

Roman try this:

if ($result = mysqli_query($con, "SELECT * FROM comments WHERE id=".mysqli_real_escape_string($con, $get_id))) {
    $row_cnt = mysqli_num_rows($result);
    printf("Result set has %d rows.\n", $row_cnt);
    mysqli_free_result($result);
}