php - 两个注意未定义变量 where 和 search

Question

Notice: Undefined variable: where
Notice: Undefined variable: search

我在所有页面上都收到了这两个通知。

我该如何解决这些？

刚刚添加了输入类型。

<input type="text" name="search" value="<?= $search; ?>" />
<input type="submit" name="submit" value="search" />

<?php
if (!isset($page)) {
    $page = 1;
}
$view = 50;
$start = ($view * $page) - $view;
//
if (isset($search)) {    
    $where = "WHERE `first` LIKE '%$search%' OR `second` LIKE '%$search%'";
} 
$i = 0;    
$query = mysql_query("SELECT `first`, `second` FROM `table_one` $where ORDER BY `id` ASC LIMIT $start, $view");
while ($row = mysql_fetch_object($query)) {
?>

Answer 1

if (isset($search)) {    
    $where = "WHERE `first` LIKE '%$search%' OR `second` LIKE '%$search%'";
}

这部分需要一个 else 语句或$where需要一个默认值。$search未设置时，将$where永远不会设置。

$where = "";
if (isset($search)) {    
    $where = "WHERE `first` LIKE '%$search%' OR `second` LIKE '%$search%'";
}