How to add attribute filtering to the ecshop search page

You can just replace the hard-coded variables of his sql query with the ones passed through the search.

sql where changes according to the filtering conditions, for example:

$filter['brand'] = isset($_REQUEST['brand']) ? trim($_REQUEST['brand']) : '';//品牌
$filter['price'] = isset($_REQUEST['price']) ? trim($_REQUEST['price']) : '';//价格
$filter['attribute'] = isset($_REQUEST['attribute']) ? trim($_REQUEST['attribute']) : '';//属性

$where = " WHERE 1";
if($filter['brand'] != ''){
    $where .= " AND brand=" . addslashes($filter['brand']);
}
if($filter['price'] != ''){
    $where .= " AND price=" . addslashes($filter['price']);
}
if($filter['attribute'] != ''){
    $where .= " AND attribute=" . addslashes($filter['attribute']);
}