搜索表单不起作用

Question

我的搜索表单不起作用。它仅在我删除名为“搜索”的“搜索栏”时才有效，因为我还有几个下拉菜单，用户可以在其中从表中获取详细信息。我简单地添加了“搜索”，以便用户可以立即找到特定信息。但是当我添加“搜索”栏时，它就不起作用了。

index.php

     <form name="formbrwse" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post" enctype="multipart/form-data">
         <input type="text" name="search">
<td>
<input type="image" name="searchbtn" id"searchbtn" src="searchbtn.fw.png"
width="166" height="38"></td>

搜索.php

if(isset($_POST['searchbtn_x'])&&($_POST['searchbtn_x']!='')&&isset($_POST['search'])&&($_POST['search']!='')){
$search=isset($_POST['search'])?$_POST['search']:"";
$search=preg_replace("#[^0-9a-z]i#","",$search);
$category=isset($_POST['category'])?$_POST['category']:"";
$location=isset($_POST['location'])?$_POST['location']:"";
$name_ddasr=isset($_POST['name_ddasr'])?$_POST['name_ddasr']:"";
$opt=isset($_POST['opt'])?$_POST['opt']:"";
//dropdown menu below
if(isset($_POST['category'],$_POST['location'],
$_POST['name_ddasr'],$_POST['opt'])){
if($_POST['search']!=''&&$_POST['category']=='All Categories'&&$_POST['location']
=='Entire Place'&&$_POST['name_ddasr']=='For sale'&&$_POST['opt']=='vrecent'){
//DDmenu comparing ends here    
$advert = "SELECT * FROM usertable WHERE adtitle LIKE '%$search%' AND 
dcrptn LIKE '%$search%' AND optionsalerent='For sale'";
$result=$conn->query($advert);
}}}

Answer 1

'For sale' 后缺少双引号。应该是'For sale'";

$advert = "SELECT * FROM usertable WHERE adtitle LIKE '%$search%' AND 
dcrptn LIKE '%$search%' AND optionsalerent='For sale';