PHP isset()有多个参数

Question

我正在尝试使用AJAX自动填充功能,并且我在使两种语言协同工作时遇到了一些问题.

当我用1 $ _POST替换所有的issets时,下面的代码片段就可以了,但是通过添加另一个$ _POST,我在第5行得到了一个错误.

<?php 

require_once '../Configuration.php';
if (isset($_POST['search_term'] . $_POST['postcode']) == true && empty ($_POST['search_term'] . $_POST['postcode']) == false) {
$search_term = mysql_real_escape_string($_POST['search_term'] . $_POST['postcode']);
$query = mysql_query("SELECT `customer_name`,`postcode` FROM `Customers` WHERE `customer_name` LIKE '$search_term%' ");
while(($row = mysql_fetch_assoc($query)) !== false) {
    //loop
    echo '<li>',$row['customer_name'] . $row['postcode'] '</li>';
}
}


?>

任何关于它为什么抛出这个错误的建议都将非常感激.谢谢.

我明白我应该使用mysqli,我只是想先得到逻辑:)

JS:

Primary.js:

$(document).ready(function() {
$('.autosuggest').keyup(function() {

    var search_term = $(this).attr('value');
    var postcode = $_GET['postcode'];
    //alert(search_term); takes what is typed in the input and alerts it
    $.post('ajax/search.php', {search_term:search_term, postcode:postcode},     function (data) {
        $('.result').html(data);
        $('.result li').click(function() {
            var result_value = $(this).text();
            $('.autosuggest').attr('value', result_value);
            $('.result').html('');

        });
    });
});
});

Answer 1

参数isset()必须是变量引用而不是表达式(在您的情况下是连接); 但您可以将多个条件组合在一起,如下所示:

if (isset($_POST['search_term'], $_POST['postcode'])) {
}

true仅当所有参数isset()都设置且不包含时,才会返回此参数null.

请注意isset($var)并isset($var) == true具有相同的效果,因此后者有点多余.

更新

表达式的第二部分使用empty()如下:

empty ($_POST['search_term'] . $_POST['postcode']) == false

出于与上述相同的原因,这是错误的.实际上,你不需要empty()这里,因为到那时你已经检查过变量是否已设置,所以你可以像这样快捷地完成整个表达式:

isset($_POST['search_term'], $_POST['postcode']) && 
    $_POST['search_term'] && 
    $_POST['postcode']

或使用等效表达式:

!empty($_POST['search_term']) && !empty($_POST['postcode'])

最后的想法

您应该考虑使用filter函数来管理输入:

$data = filter_input_array(INPUT_POST, array(
    'search_term' => array(
        'filter' => FILTER_UNSAFE_RAW,
        'flags' => FILTER_NULL_ON_FAILURE,
    ),
    'postcode' => array(
        'filter' => FILTER_UNSAFE_RAW,
        'flags' => FILTER_NULL_ON_FAILURE,
    ),
));

if ($data === null || in_array(null, $data, true)) {
    // some fields are missing or their values didn't pass the filter
    die("You did something naughty");
}

// $data['search_term'] and $data['postcode'] contains the fields you want

顺便说一句,您可以自定义过滤器以检查提交值的各个部分.

Answer 2

参数isset()应该用逗号(,)而不是点号(.)分隔.您当前的代码将变量连接成一个参数,而不是将它们作为单独的参数传递.

因此原始代码将变量评估为统一string值:

isset($_POST['search_term'] . $_POST['postcode']) // Incorrect

正确的表单将它们作为变量单独评估:

isset($_POST['search_term'], $_POST['postcode']) // Correct

Answer 3

您只需要:

if (!empty($_POST['search_term']) && !empty($_POST['postcode']))

isset && !empty 是多余的.