php - 将空白数据插入数据库的字段

Question

我已将我的代码与网站上其他地方的代码进行了比较，看不到任何不一致之处，但由于某种原因，记录以空白数据进入我的数据库，这是我的代码。

<?php

include '../includes/connect.php';
include '../header.php';

echo '<h2>Create a Sub category</h2>';
if($_SESSION['signed_in'] == false | $_SESSION['user_level'] != 1 )
{
//the user is not an admin
echo 'Sorry, you do not have sufficient rights to access this page.';
}
else
{
//the user has admin rights
if($_SERVER['REQUEST_METHOD'] != 'POST')
{
    //the form hasn't been posted yet, display it
    echo '<form method="post" action="">
        Category name: ';
        $sql = "SELECT cat_id, cat_name, cat_description FROM categories";
        $result = mysql_query($sql);
    echo '<select name="topic_cat">';
                while($row = mysql_fetch_assoc($result))
                {
                    echo '<option value="' . $row['cat_id'] . '">' . $row['cat_name'] . '</option>';
                }
            echo '</select><br />';


    echo 'Sub category name: <input type="text" name="sub_cat_name" /><br />
        Sub category description:<br /> <textarea name="sub_desc" /></textarea><br /><br />
        <input type="submit" value="Add Sub Category" />
     </form>';
}
else
{

    //the form has been posted, so save it
    $sql = "INSERT INTO subcategories(c_id, sub_cat_name, sub_desc)
       VALUES('" . $_POST['categories.cat_id'] . "', '" . $_POST['sub_cat_name'] . "', '" . $_POST['sub_desc'] . "')";
    $result = mysql_query($sql) or die (mysql_error());
            echo 'The sub category <b>' . $row['sub_cat_name'] . '</b> has been added under the main category <b>' . $row['cat_name'] . '</b>';
    if(!$result)
    {
        //something went wrong, display the error
        echo 'Error' . mysql_error();

    }
}
}
; ?>

我的类别表的结构如下..

• cat_id
• cat_desc

我的子类别表的结构如下..

• id(AI)
• c_id
• 子猫名称
• sub_desc

如果我没有提供足够的信息，请告诉我。

Answer 1

您似乎没有将 $POST 变量读入您在查询中使用的变量。您可能想要这样的东西:

$sub_cat_name = mysql_real_escape_string($_POST['sub_cat_name']);
// repeat for other variables.