php - 未定义索引 PHP : Can't Find Form Values

Question

完全是 PHP 新手，但正在尝试将简单的表单提交到 MySQL 数据库。我不断收到通知: undefined index :表单输入变量上的警告。这里可能有什么问题。该表单位于提交到 process.php 文件的单独 PHP 页面上。

表单代码:

<form name="example" id="example" method="POST" action="process.php" enctype="multipart/form-data">
    <p>
        <label for="first_name">First Name:</label>
        <input size="20" name="first_name" id="first_name" />
    </p>
    <p>
        <label for="city">city</label>
        <input size="20" name="city" id="city" />
    </p>
    <p>
        <label for="state">state</label>
        <input size="20" name="state" id="state" />
    </p>
    <p>
        <label for="zip">zip</label>
        <input size="20" name="zip" id="zip" />
    </p>
    <p>
        <label for="email">e-mail</label>
        <input size="20" name="email" id="email" />
    </p>
    <p>
        <label for="form_upload">file</label>
        <input size="40" type="file" name="form_data" id="form_data" />
    </p>
    <p>
        <input type="submit" value="Submit form" name="submit" />
    </p>
</form>

流程.php

<?php
   mysql_connect("localhost", 'root', '') or die('Could not connect:' . mysql_error());
   mysql_select_db("practice") or die(mysql_error());
   mysql_query("CREATE TABLE user (id INT(5)NOT NULL AUTO, name VARCHAR(30), email     VARCHAR(40), city VARCHAR(40), state VARCHAR(3), zip INT(5) )");
   if (isset($_POST)) {
       $name  = $_POST['first_name'];
       $email = $_POST['email'];
       $city  = $_POST['city'];
       $state = $_POST['state'];
       $zip   = $_POST['zip'];
   }
   mysql_query("INSERT INTO user VALUES('$name', '$email', '$city', '$state', '$zip')");
?>

Answer 1

我想你应该改变这个

    if (isset($_POST)){

并给出这样的索引

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

还有

将查询更改为

  mysql_query("INSERT INTO user (name , email, city,state, zip)
               VALUES('$name', '$email', '$city', '$state', '$zip')" );

并且您应该在插入变量之前像这样转义它们。

  $name = mysql_real_escape_string($name) ;
 // and so on 

最后一件事是为什么每次提交时都创建表？你应该检查是否存在。