Question

您好我无法弄清楚我的代码有什么问题。还没有太多的PHP经验。有人可以告诉我，我做错了什么？

这是我的代码：

<?php
   include 'mysql_connect.php';
if (!isset($_POST['submit'])) {
    $fuelQuery2 = sprintf("UPDATE fuel_price SET `Price` = '%s' WHERE FuelType = '%s' LIMIT 1",
                        mysql_real_escape_string($_POST['inputPrice']),
                        mysql_real_escape_string($_POST['fueltype']));

    $Result = mysql_query($fuelQuery2);
    if($Result){
        echo 'Price has been updated!';
    } else{
        echo 'Failed to update price!';
    }
} else{
    echo 'No form submitted';
}


?>

<h1>Update Oil Price</h1>

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
Oil Price:<input name="inputPrice" type="text" value=""/>

Product
<select name="fueltype">
<option value="Oil">Kero</option>
<option value="Diesel">Diesel</option>
<option value="RedDiesel">Red Diesel</option>
</select>

<input type="submit" name="submit" value="Modify" />
</form>

Answer 1

这很简单，改变

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

到

if(isset($_POST['submit'])) { //Only execute the query when the form is submitted

您的原始代码告诉PHP在未提交表单时执行查询（请注意我删除了！）而不是在何时提交。您收到的通知告诉您，您为查询抓取的$_POST变量不存在（因为代码在提交表单之前运行）。

另外，请查看PDO。 mysql_函数族不再是与数据库层交互的首选方法。

Answer 2

PHP

在mysql_connect.php中，请确保致电mysql_connect()和mysql_select_db()。

然后您可以将代码调整为以下内容：

<?php
    include 'mysql_connect.php';
    if ('POST' == $_SERVER['REQUEST_METHOD'] and
        isset($_POST['fuel_type']) and
        isset($_POST['oil_price'])) {
        $fuel_type = mysql_real_escape_string($_POST['fuel_type']);
        $oil_price = mysql_real_escape_string($_POST['oil_price']);

        $SQL = "UPDATE `fuel_price`
                SET `Price` = '$oil_price'
                WHERE `FuelType` = '$fuel_type'";

        if(mysql_query($SQL)) {
            echo 'Price updated.';
        } else {
            echo 'Failed to update.';
        }
    }
?>

HTML表格

PHP_SELF中不需要action，您可以将其留空以提交到同一页面。

<form action="" method="post">
    <label for="oil_price">Oil Price</label>
    <input name="oil_price" id="oil_price" type="text" value="" />

    <label for="fuel_type">Product</label>
    <select name="fuel_type" id="fuel_type">
        <option value="Oil">Kerosene</option>
        <option value="Diesel">Diesel</option>
        <option value="RedDiesel">Red Diesel</option>
    </select>

    <input type="submit" name="submit" value="Modify" />
</form>

根据选项选择更新mysql记录

2 个答案:

PHP

HTML表格