Php 从"；中获取行值；id"；柱

在下面的代码中，我希望获得列“id”的行结果作为$selectedmovieid的结果。“CommonId”是主键属性。很抱歉，不知道如何正确使用mysql\u fetch\u assoc

<?php
require ("connect-comment.php");
$deleteid=$_GET['commentid'];
$query1=mysql_query("SELECT id FROM comment WHERE commentid='$deleteid'");
$selectedmovieid= mysql_fetch_assoc($query1);
$query2=mysql_query("DELETE FROM comment WHERE commentid='$deleteid'");
header("Location: reload.php?id=$selectedmovieid");
?>

尝试更改

$deleteid=$_GET['commentid'];
// ...
header("Location: reload.php?id=$selectedmovieid");

到

此外，正如佩卡正确地建议的那样，试着阅读和

作为旁注，您应该不要为
位置：
标题重定向使用相对路径。RFC指定此字段应包含完整URL，虽然许多浏览器将正确解释相对路径，但不应依赖此行为。换句话说，
Location:reload.php？id=…
应该是
Location:http://mysite.tld/reload.php?id=

编辑尝试以下示例代码的完整版本：

<?php

  require ("connect-comment.php");
  $deleteid = mysql_real_escape_string($_GET['commentid']);

  // Added LIMIT 1 to the query, because you are only using one result
  if (!$query1 = mysql_query("SELECT `id` FROM `comment` WHERE `commentid` = '$deleteid' LIMIT 1")) {
    // Do NOT show the output of mysql_error() to the user in a production environment!
    exit("Something went wrong with query 1: ".mysql_error());
  } else if (mysql_num_rows($query1) < 1) {
    exit("No results from query 1");
  }
  $selectedmovieid = mysql_fetch_assoc($query1);
  $selectedmovieid = $selectedmovieid['id']; // $selectedmovieid now contains the id you want

  if (!$query2 = mysql_query("DELETE FROM `comment` WHERE `commentid` = '$deleteid'")) {
    // Do NOT show the output of mysql_error() to the user in a production environment!
    exit("Something went wrong with query 2: ".mysql_error());
  }

  // If we get this far, everything should be fine
  // You still need a full URL here though, not a relative path...
  header("Location: reload.php?id=$selectedmovieid");

?>

如果您键入
http://php.net/
然后是您需要了解的函数名称，您将进入PHP手册中的页面。手册几乎总是提供一个例子。哎哟这么多未初始化的用户输入…您永远不应该将从用户获取的内容（尤其是GET参数）插入到SQL语句中。了解mysql\u fetch\u assoc（）。只需在文档中查找即可。要详细说明Till的含义：+1@TillHelgeHelwig，尤其是在
DELETE
语句中-如果我请求
http://yourdomain.tld/yourpage.php?commentid=1“+或+'0'+=+'0
？
$deleteid = mysql_real_escape_string($_GET['commentid']);
// ...
header("Location: reload.php?id={$selectedmovieid['id']}");

<?php

  require ("connect-comment.php");
  $deleteid = mysql_real_escape_string($_GET['commentid']);

  // Added LIMIT 1 to the query, because you are only using one result
  if (!$query1 = mysql_query("SELECT `id` FROM `comment` WHERE `commentid` = '$deleteid' LIMIT 1")) {
    // Do NOT show the output of mysql_error() to the user in a production environment!
    exit("Something went wrong with query 1: ".mysql_error());
  } else if (mysql_num_rows($query1) < 1) {
    exit("No results from query 1");
  }
  $selectedmovieid = mysql_fetch_assoc($query1);
  $selectedmovieid = $selectedmovieid['id']; // $selectedmovieid now contains the id you want

  if (!$query2 = mysql_query("DELETE FROM `comment` WHERE `commentid` = '$deleteid'")) {
    // Do NOT show the output of mysql_error() to the user in a production environment!
    exit("Something went wrong with query 2: ".mysql_error());
  }

  // If we get this far, everything should be fine
  // You still need a full URL here though, not a relative path...
  header("Location: reload.php?id=$selectedmovieid");

?>