dedecms只搜索指定的栏目

<select id="category-select">
    <option value="all">所有栏目</option>
    <option value="column1">栏目1</option>
    <option value="column2">栏目2</option>
</select>
<input type="text" id="search-input" placeholder="搜索...">
<button onclick="search()">搜索</button>

<script>
function search() {
    var category = document.getElementById('category-select').value;
    var keyword = document.getElementById('search-input').value;
    if (category === 'all') {
        window.location.href = '/plus/search.php?keyword=' + encodeURIComponent(keyword);
    } else {
        window.location.href = '/plus/search.php?keyword=' + encodeURIComponent(keyword) + '&channelid=' + category;
    }
}
</script>

// 在搜索逻辑中添加栏目限制
if (!empty($_GET['channelid'])) {
    $channelid = intval($_GET['channelid']);
    $whereSql .= " AND channel = $channelid";
}

// 修改SQL查询语句
$sql = "SELECT * FROM `dede_archives` WHERE `$searchtype` LIKE '%$keyword%' $whereSql";