我尝试使用以下三个选项过滤结果列表：
主要类别，子类别和搜索
两个类别选项是下拉列表，搜索是文本框。
到目前为止，这是我的代码：
files.php
if (!isset($_GET['filter'])){
$_GET['filter'] = "";
}
if (!isset($_GET['search'])){
$_GET['search'] = "";
}
if (!isset($_GET['subcategory'])){
$_GET['subcategory'] = "";
}
//过滤结果的表单：
<form method="get">
Category: <select name="filter">
<option <?php if(!isset($_GET['filter'])){echo 'selected';} ?> value="">-- Select Category --</option>
<option <?php if($_GET['filter'] == "1") {echo 'selected';} ?> value="1">View Vehicles Only</option>
<option <?php if($_GET['filter'] == "2") {echo 'selected';} ?> value="2">View Lighting Equiptment</option>
</select><br /><br />
<?php
if(isset($_GET['filter'])){
if($_GET['filter'] != ""){
echo 'SubCategory: <select name="subcategory">';
$sub_categories = getsubcategories($_GET['filter']);
foreach ($sub_categories as $cat){
echo '<option value = "'.$cat['cat_id'].'">'.$cat['cat_name'].'</option>';
}
echo '</select><br /><br />';
}
}
?>
Search Files: <input type="text" name="search" <?php if(isset($_GET['search'])){echo 'value="'.$_GET['search'].'"';}?> placeholder=" Enter a search term..." />
<br /><br /><center><input type="submit" class="btn btn-default" value="Update Results"/> <a href="files.php" class="btn btn-default">Reset Filters</a></center>
</form>
//调用函数来检索结果：
$files = getbycategory($_GET['filter'], $_GET['search'], $_GET['subcategory']);
//循环结果：
foreach($files as $file){
echo'<div class="col-lg-" id="file-'.$file['part_id'].'">
<div class="file-list-item first" id="">';
if ($file['image_url'] == "")
{
echo '<img class="file-image" height="120px" width="180px" src="'.baseurl.'/resources/img/no-image.png" />';
} else {
echo '<img class="file-image" height="120px" width="180px" src="'.$file['image_url'].'" />';
}
echo '
<div class="file-text">
<h3><strong>'.$file['part_name'].'</strong></h3>
Submitted by: '.$file['submitter'].'<br/>
Author: '.$file['author'].'<br />
Category: '.ucfirst($file['subcategory']).'<br />
Description: '.substr($file['description'],0,45).'...
</div>
<div class="download">
<a target="_blank" href="'.$file['download_url'].'" class="btn-success btn btn-default">Download</a>
<a href="'.baseurl.'/broken.php?id='.$file['part_id'].'" class="btn btn-default">Report as Broken</a><br /><br />';
if($file['is_broken']){
echo '<span class="broken"><i data-toggle="tooltip" data-placement="left" id="broken" title="This file has been reported as broken by \'Alcon H\' and is awaiting review." class="fa fa-warning fa-2x"></i></span>';
}
echo '
</div>
</div>
</div>';
};
file_functions.php
//这是检索结果的函数：
function getbycategory($category, $search, $subcategory){
global $db;
$sm = $db->prepare("SELECT * FROM parts WHERE main_category = :category AND active = 1 AND subcategory = :subcategory AND part_name LIKE :search");
if ($category == ""){
$category = '%';
$sm->bindParam(":category", $category, PDO::PARAM_STR);
} else {
$sm->bindParam(":category", $category, PDO::PARAM_STR);
}
if ($subcategory ==""){
$subcategory = '%';
$sm->bindParam(":subcategory", $subcategory, PDO::PARAM_STR);
} else {
$sm->bindParam(":subcategory", $subcategory, PDO::PARAM_STR);
}
if ($search == ""){
$search = '%'.$search.'%';
} else {
$sm->bindParam(":search", $search, PDO::PARAM_STR);
}
$sm->execute();
return $sm->fetchAll();
}
我收到的错误是：
PHP Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens' in /var/www/html/partsdb/resources/file_functions.php:74\nStack trace:\n#0 /var/www/html/partsdb/resources/file_functions.php(74): PDOStatement->execute()\n#1 /var/www/html/partsdb/files.php(18): getbycategory('', '', '')\n#2 {main}\n thrown in /var/www/html/partsdb/resources/file_functions.php on line 74, referer: http://localhost/partsdb/files.php
file_functions.php的第74行就是它的执行位置。
谁能看到我哪里出错了？
答案 0 :(得分：1)
如果只在搜索字符串为空时才会发生这种情况，那是因为：
if ($search == ""){
$search = '%'.$search.'%';
} else {
$sm->bindParam(":search", $search, PDO::PARAM_STR);
}
仅在$search变量不是空字符串时才绑定参数。要修复它，您可以将其修改为：
if ($search == ""){
$search = '%'.$search.'%';
}
$sm->bindParam(":search", $search, PDO::PARAM_STR);
因此它始终将准备好的语句与搜索字段绑定在一起。虽然如果空的$ search将被替换为字符串%%，因此只返回等于字符串%%的值，这似乎有点奇怪，因为我相信你更喜欢那里的LIKE语句，尽管是一个与此不同的问题。
答案 1 :(得分：0)
首先将Ternary operator与isset()一起使用。
$category = isset($_GET["category"]) ? $_GET["category"] : "";
声明一个数组来保存参数。
$params = array();
然后将查询存根设置为变量。
$sql = "SELECT * FROM parts ";
将标志设置为0以从WHERE切换为AND以获取2个或更多参数
开始构建查询的其余部分，增加$flag向$params数组添加参数
if($category != ""){
$sql .= " WHERE main_category = ?";
$params[] = $category;
$flag++;
}
如果标志＆gt; 0使用AND而不是WHERE
if($search != ""){
if($flag > 0){
$sql .= " AND search = ?";
}else{
$sql .= " WHERE search = ?";
}
$params[] =$search;
$flag++;
使用＆＃34;懒惰＆＃34;绑定将数据传递给执行。
$sm->execute($params);
最终代码。
<?php
$category = isset($_GET["category"]) ? $_GET["category"] : "";
$search = isset($_GET['search']) ? $_GET['search'] : "";
$subcategory = isset($_GET['subcategory']) ? $_GET['subcategory'] : "";
$params = array();
function getbycategory($category, $search, $subcategory){
global $db;
$sql = "SELECT * FROM parts ";
$flag = 0;
if($category != ""){
$sql .= " WHERE main_category = ?";
$params[] = $category;
$flag++;
}
if($search != ""){
if($flag > 0){
$sql .= " AND search = ?";
}else{
$sql .= " WHERE search = ?";
}
$params[] =$search;
$flag++;
}
if($subcategory != ""){
if($flag > 0){
$sql .= " AND subcategory = ?";
}else{
$sql .= " WHERE subcategory = ?";
}
$params[] = $subcategory;
}
echo $sql; //Remove after testing
print_r($params);//Remove after testing
$sm = $db->prepare($sql);
$sm->execute($params);
return $sm->fetchAll();
}
getbycategory($category, $search, $subcategory);
}
阅读您的代码我看到$category = '%';如果您需要LIKE而不是=，则需要先准备全文字。
$category = "%$category%";