13

我的if(isset($_POST['submit']))代码有一点问题。我想要的是在脚本打开时不会出现一些回声和表格，但我确实希望它在单击表单的提交按钮时显示。问题是，当我包含该if(isset($_POST['submit']))功能时，当我单击提交按钮时，它根本不显示回声和表格。为什么会这样，请您帮我解决这个问题。

下面是代码：

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>

<title>Exam Interface</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>

<p><strong>NOTE: </strong>If a search box is left blank, then the form will search for all data under that specific field</p>

<form action="exam_interface.php" method="post" name="sessionform">        <!-- This will post the form to its own page"-->
<p>Session ID: <input type="text" name="sessionid" /></p>      <!-- Enter Session Id here-->
<p>Module Number: <input type="text" name="moduleid" /></p>      <!-- Enter Module Id here-->
<p>Teacher Username: <input type="text" name="teacherid" /></p>      <!-- Enter Teacher here-->
<p>Student Username: <input type="text" name="studentid" /></p>      <!-- Enter User Id here-->
<p>Grade: <input type="text" name="grade" /></p>      <!-- Enter Grade here-->
<p>Order Results By: <select name="order">
<option value="ordersessionid">Session ID</option>
<option value="ordermoduleid">Module Number</option>
<option value="orderteacherid">Teacher Username</option>
<option value="orderstudentid">Student Username</option>
<option value="ordergrade">Grade</option>
</select>
<p><input type="submit" value="Submit" /></p>
</form>

<?php

$username="xxx";
$password="xxx";
$database="mobile_app";

mysql_connect('localhost',$username,$password);

@mysql_select_db($database) or die("Unable to select database");

$sessionid = isset ($_POST['sessionid']) ? $_POST['sessionid'] : "";
$moduleid = isset ($_POST['moduleid']) ? $_POST['moduleid'] : "";
$teacherid = isset ($_POST['teacherid']) ? $_POST['teacherid'] : "";
$studentid = isset ($_POST['studentid']) ? $_POST['studentid'] : "";
$grade = isset ($_POST['grade']) ? $_POST['grade'] : "";
$orderfield = isset ($_POST['order']) ? $_POST['order'] : "";

$sessionid = mysql_real_escape_string($sessionid);
$moduleid = mysql_real_escape_string($moduleid);
$teacherid = mysql_real_escape_string($teacherid);
$studentid = mysql_real_escape_string($studentid);
$grade = mysql_real_escape_string($grade);

switch ($orderfield) {
    case 'ordersessionid': $orderfield = 'gr.SessionId';
    break;
    case 'ordermoduleid': $orderfield = 'm.ModuleId'; 
    break;
    case 'orderteacherid': $orderfield = 's.TeacherId';
    break;
    case 'orderstudentid': $orderfield = 'gr.StudentId'; 
    break;
    case 'ordergrade': $orderfield = 'gr.Grade';
    break;
}

$ordertable = $orderfield;

$result = mysql_query("SELECT * FROM Module m INNER JOIN Session s ON m.ModuleId = s.ModuleId JOIN Grade_Report gr ON s.SessionId = gr.SessionId JOIN Student st ON gr.StudentId = st.StudentId WHERE ('$sessionid' = '' OR gr.SessionId = '$sessionid') AND ('$moduleid' = '' OR m.ModuleId = '$moduleid') AND ('$teacherid' = '' OR s.TeacherId = '$teacherid') AND ('$studentid' = '' OR gr.StudentId = '$studentid') AND ('$grade' = '' OR gr.Grade = '$grade') ORDER BY $ordertable ASC");

$num=mysql_numrows($result);

if(isset($_POST['submit'])){

echo "<p>Your Search: <strong>Session ID:</strong> "; if (empty($sessionid))echo "'All Sessions'"; else echo "'$sessionid'";echo ", <strong>Module ID:</strong> "; if (empty($moduleid))echo "'All Modules'"; else echo "'$moduleid'";echo ", <strong>Teacher Username:</strong> "; if (empty($teacherid))echo "'All Teachers'"; else echo "'$teacherid'";echo ", <strong>Student Username:</strong> "; if (empty($studentid))echo "'All Students'"; else echo "'$studentid'";echo ", <strong>Grade:</strong> "; if (empty($grade))echo "'All Grades'"; else echo "'$grade'"; "</p>";

echo "<p>Number of Records Shown in Result of the Search: <strong>$num</strong></p>";

echo "<table border='1'>
<tr>
<th>Student Id</th>
<th>Forename</th>
<th>Session Id</th>
<th>Grade</th>
<th>Mark</th>
<th>Module</th>
<th>Teacher</th>
</tr>";

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

 echo "<tr>";
  echo "<td>" . $row['StudentId'] . "</td>";
  echo "<td>" . $row['Forename'] . "</td>";
  echo "<td>" . $row['SessionId'] . "</td>";
  echo "<td>" . $row['Grade'] . "</td>";
  echo "<td>" . $row['Mark'] . "</td>";
  echo "<td>" . $row['ModuleName'] . "</td>";
  echo "<td>" . $row['TeacherId'] . "</td>";
  echo "</tr>";
}

echo "</table>";

}

mysql_close();


 ?>

</body>
</html>

任何帮助将不胜感激，谢谢。

4

8 回答 8

38

您需要为您的提交<input>命名，否则将无法使用$_POST['submit']：

<p><input type="submit" value="Submit" name="submit" /></p>
于 2011-10-15T03:12:23.320 回答
15

你在检查什么

if(isset($_POST['submit']))

但是没有名为“提交”的变量名。好吧，我想让你明白为什么它不起作用。让我们想象一下，如果你给你的提交按钮名称删除 <input type="submit" value="Submit" name="delete" />并检查if(isset($_POST['delete']))它然后它在这个代码中工作你没有给出任何名称来提交按钮并检查它是否存在与isset();函数所以 php 没有找到任何变量像“提交”所以它现在不工作试试这个：

<input type="submit" name="submit" value="Submit" />
于 2011-10-15T08:03:08.803 回答
11

你从来没有命名你的提交按钮，所以就表单而言，它只是一个动作。

任何一个：

  1. 命名提交按钮 ( <input type="submit" name="submit" ... />)
  2. 改为测试if (!empty($_POST))以检测数据何时发布。

请记住，$_POST超全局中的键只出现在命名的输入元素中。因此，除非元素具有 name 属性，否则它不会通过$_POST(或$_GET/ $_REQUEST)

于 2011-10-15T03:11:50.790 回答
2

这有什么问题？

<form class="navbar-form navbar-right" method="post" action="login.php">
  <div class="form-group">
    <input type="email" name="email" class="form-control" placeholder="email">
    <input type="password" name="password" class="form-control" placeholder="password">
  </div>
  <input type="submit" name="submit" value="submit" class="btn btn-success">
</form>

登录.php

if(isset($_POST['submit']) && !empty($_POST['submit'])) {
  // if (!logged_in()) 
  echo 'asodj';
}
于 2017-03-15T18:18:14.230 回答
1

您必须为提交按钮命名

<input type="submit" value"Submit" name="login">

然后你可以调用按钮$_POST['login']

于 2015-03-16T10:51:11.907 回答
1

该$_post函数需要名称值，例如：

<input type="submit" value"Submit" name="example">

称呼

$var = strip_tags($_POST['example']);
if (isset($var)){
    // your code here
}
于 2016-09-27T22:03:02.543 回答
0

另一种选择是使用

$_SERVER['REQUEST_METHOD'] == 'POST'
于 2018-10-19T22:21:19.607 回答
0

如果 (isset($_POST[submit]) ，任何时候尝试这个函数都会显示错误代码（不要直接访问超级全局 $_POST 数组）

于 2021-08-04T19:50:50.617 回答