Question

我只是想通过ID对评论进行排序，但我没有运气。无法弄清楚该怎么做，因为这让我很困惑：articleid='" . mysql_real_escape_string($_GET['id']) . "'

你们是否碰巧知道如何通过DESC中的id订购评论？谢谢！

<?php

$amount_get = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "'"); $comments = mysql_num_rows($amount_get);

$grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "'");


if (mysql_num_rows($grab)==0) {

    echo "<div class='alert alert-note-x'>Sorry, it looks like their are no comments to be displayed, check back later!</div>";
}

    while($row = mysql_fetch_array($grab)){

    ?>

Answer 1

首先，你要做两次相同的SELECT次。这是非常不必要的，因为您可以计算行并从单个查询中获取数据。除此之外，还可以使用评论表的唯一ID替换commentid并进行设置。将DESC替换为ASC以反转排序顺序。

<?php
    $grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' ORDER BY commentid DESC");
    $comments = mysql_num_rows($grab);

    if (mysql_num_rows($grab)==0) {
        echo "<div class='alert alert-note-x'>Sorry, it looks like their are no comments to be displayed, check back later!</div>";
    }

    while($row = mysql_fetch_array($grab)){

?>

Answer 2

添加ORDER BY子句

$grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' ORDER BY articleid, ID DESC");

您的查询容易被SQL Injection攻击，请阅读以下文章以防止它，

How can I prevent SQL injection in PHP?

Answer 3

试试这个

$grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' order by articleid desc");

Answer 4

我认为你的评论表后面有一列id，所以：

$grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' ORDER BY id DESC");

这是一个sql的东西来排序它，而不是php，所以你只需要修改你的sql语句。

Answer 5

$amount_get = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' ORDER BY id DESC "); 

$grab = mysql_query("SELECT * FROM comment WHERE articleid='" . mysql_real_escape_string($_GET['id']) . "' ORDER BY id DESC");

Answer 6

三点建议：

1）在字符串变量中完成“select”语句（如下所示;它使调试更容易）

2）考虑使用预准备语句而不是原始“select”（或更新或删除！）。

它可以帮助提高性能。但它使您的PHP 更多更安全！

3）考虑远离（不推荐使用的）mysql_query（）语法

<?php

  $sql = 
    "SELECT * FROM comment WHERE articleid='" . 
    mysql_real_escape_string($_GET['id']) . "' order by articleid desc";
  $amount_get = mysql_query($sql); 
  $comments = mysql_num_rows($amount_get);

  $sql = 
    "SELECT * FROM comment WHERE articleid='" . 
    mysql_real_escape_string($_GET['id']) . "'order by articleid desc";
  $grab = mysql_query($sql);
  ...

这是mySQLi和PDI API上的一个很好的链接，它取代了旧的mysql_query（）语法：

mysqli or PDO - what are the pros and cons?

这是预备陈述的良好链接：

http://forum.codecall.net/topic/44392-php-5-mysqli-prepared-statements/#axzz2Dazi7pQ4

Answer 7

您可以在查询中使用order by子句

    <?php
$getarticles = array();
$getarticles = mysql_query("SELECT * FROM comment order by articleid desc");

if(empty($getarticles)){
echo "<div class='alert alert-note-x'>Sorry, it looks like their are no comments to be displayed, check back later!</div>";
}
echo "<pre>";
print_r($getarticles);
echo "</pre>";

    for($i=0;$i<count($getarticles);$i++){
//display
}

    ?>

ORDER BY id DESC

7 个答案: