如何过滤数据以仅显示特定的product_type

Question

$search_exploded = explode (" ", $search);
 
$x = "";
$construct = "";  
    
foreach($search_exploded as $search_each)
{
$x++;
if($x==1)
$construct .="product_type LIKE '%$search_each%'";
else
$construct .="AND product_type LIKE '%$search_each%'";
    
}
?>

我目前正在尝试在此数据视图上实施搜索引擎。即将尝试使用下拉菜单供用户查看哪种类型的产品。 我一直在使用mysql，它工作正常。但是现在我想要做的就是把它改成mysqli，现在一切都出错了

<?php
    //current URL of the Page. cart_update.php redirects back to this URL
	$current_url = base64_encode($url="http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']);
    
	$results = $mysqli->query("SELECT * FROM produk2 ORDER BY id ASC WHERE $construct " );
        if ($results) { 
	
        //fetch results set as object and output HTML
        while($obj = $results->fetch_object())
        {
	    echo '<div class="product">'; 
            echo '<form method="post" action="cart_update.php">';
	    echo '<div class="product-thumb"><img src="images/'.$obj->product_img_name.'"></div>';
            echo '<div class="product-content"><h3>'.$obj->product_name.'</h3>';
            echo '<div class="product-desc">'.$obj->product_desc.'</div>';
            echo '<div class="product-info">';
	    echo 'Price '.$currency.$obj->price.' | ';
            echo 'Qty <input type="text" name="product_qty" value="1" size="3" />';
	    echo '<button class="add_to_cart">Add To Cart</button>';
	    echo '</div></div>';
            echo '<input type="hidden" name="product_code" value="'.$obj->product_code.'" />';
            echo '<input type="hidden" name="type" value="add" />';
	    echo '<input type="hidden" name="return_url" value="'.$current_url.'" />';
            echo '</form>';
            echo '</div>';
        }
    
        }
    ?>