注意:未定义的索引:c: xampp htdocs ds ds dsearch.php中的dlocat

Question

我第一次加载HTML表单时会出现以下错误。一旦我从下拉列表中选择选项。所有操作都很好。

我发现的错误是第一次：注意：未定义的索引：c： xampp htdocs ds ds dsearch.php在第48行48

上

    <?php
        $queryfilter = "SELECT distinct dlocation FROM desmit";
        $resultfilter = mysql_query($queryfilter);
        $dlocationfilter=$_POST['dlocation'];
        echo $dlocationfilter;
    ?>
     <form name='frmSearch' action='' method='post'>
        <select name="dlocation">
        <option value="All">All </option>
        <?php
        while ($line = mysql_fetch_array($resultfilter, MYSQL_ASSOC)) {
        ?>
        <option value="<?php echo $line['dlocation'];?>"> <?php echo $line['dlocation'];?> </option>
        <?php
        }
        ?>
        </select>

Answer 1

我不知道您要做什么，而是使用php的isset((函数来获取$ _post value

<?php
            $queryfilter = "SELECT distinct dlocation FROM desmit";
            $resultfilter = mysql_query($queryfilter);
            $dlocationfilter= isset($_POST['dlocation']) ? $_POST['dlocation'] : '';
            echo $dlocationfilter;
        ?>

Answer 2

它说不存在数组的索引，因此检查索引存在：

<?php
$queryfilter = "SELECT distinct dlocation FROM desmit";
$resultfilter = mysql_query($queryfilter);
$dlocationfilter=f(isset($_POST['dlocation']) && $_POST['dlocation']) ? $_POST['dlocation'] : null;
echo $dlocationfilter;
?>
<form name='frmSearch' action='' method='post'>
    <select name="dlocation">
        <option value="All">All </option>
        <?php
        while ($line = mysql_fetch_array($resultfilter, MYSQL_ASSOC)) {
            if(isset($line['dlocation']) && $line['dlocation']) {
            ?>
                <option value="<?php echo $line['dlocation'];?>"> <?php echo $line['dlocation'];?> </option>
            <?php
            }
        }
        ?>
    </select>

Answer 3

将此行添加到您的.htaccess中以隐藏注意：

php_flag display_errors off