这当然是您必须在服务器端解决的问题，只有省略URL中的参数，才能在访问$_GET 大堆

您应该根据是否设置值动态构建参数数组。

示例：

$args = array();

foreach(array(\'s\', \'country\', \'year\') as $key)
{
    // if key is available and not empty, include argument in the query
    if(isset($_GET[$key]) && trim($_GET[$key]) !== \'\')
    {
        $args[$key] = $_GET[$key];
    }
}

// \'s\' is neccessary for a search query, so only continue if it\'s available
if(isset($args[\'s\']))
{
    $the_query = new WP_Query($args);
    ...
}

Update:

在弄清楚这个国家插件是什么之后，我看了一下。它处理查询，但只检查国家/地区键是否存在，而不检查其是否为空，并对全局查询对象执行此检查，因此即使自定义查询中没有国家/地区，它将出现在全局查询对象中，因为插件将国家/地区键添加到将自动获取的变量列表中（如果您不知道，WordPress将自动为您查询帖子）。您可能想联系插件作者并告诉他有关问题的情况，以便他能够修复它，在此之前，这里有一个针对当前版本的快速而肮脏的修复：

// Hooks...
add_filter(\'posts_join\', \'country_search_join\', 10, 2);
add_filter(\'posts_where\', \'country_search_where\', 10, 2);
add_filter(\'posts_groupby\', \'country_search_groupby\', 10, 2);
add_filter(\'query_vars\', \'country_queryvars\');
add_action(\'init\', \'country_flush_rewrite_rules\');
add_action(\'generate_rewrite_rules\', \'country_add_rewrite_rules\');
add_action(\'plugins_loaded\', \'country_widget_init\');
add_action(\'admin_menu\', \'manage_countries_menu\');


// Join clause for the META table if a country is queried.
function country_search_join($join, &$wp_query)
{
    global $wpdb;

    if(isset($wp_query->query_vars[\'country\']) && trim($wp_query->query_vars[\'country\']) !== \'\') {
        $join .= " left join $wpdb->postmeta on $wpdb->posts.ID = $wpdb->postmeta.post_id ";
    }
    return $join;
}


// Add a where clause if a country is queried.
function country_search_where($where, &$wp_query)
{
    global $wpdb;

    if(isset($wp_query->query_vars[\'country\']) && trim($wp_query->query_vars[\'country\']) !== \'\') {
        $where = $where . " and {$wpdb->postmeta}.meta_key = \'Country\' and {$wpdb->postmeta}.meta_value = \'" . $wp_query->query_vars[\'country\'] . "\' ";
    }
    return $where;
}


// Add a group by clause if a country is queried to make sure posts are only returned once.
function country_search_groupby($groupby, &$wp_query)
{
    global $wpdb;

    if(!isset($wp_query->query_vars[\'country\']) || trim($wp_query->query_vars[\'country\']) === \'\') {
        return $groupby;
    }

    // Group on post ID
    $mygroupby = "{$wpdb->posts}.ID";

    // Is this group by already there?
    if(preg_match( "/$mygroupby/", $groupby)) {
        return $groupby;
    }

    // Is the group by empty?
    if(!strlen(trim($groupby))) {
        return $mygroupby;
    }

    // Append new group by clause.
    return $groupby . ", " . $mygroupby;
}

现在我已经了解了插件的具体功能，我建议不要使用自定义查询，WordPress的查询应该可以了，比如这样的查询应该可以：

<?php while ( have_posts() ) : the_post(); ?>

    <h3 class="search-title"><?php country_tag($post->ID); ?><a href="#" data-siteurl="<?php bloginfo(\'url\'); ?>" rel="<?php the_ID(); ?>" title="<?php the_title_attribute(); ?>" class="search-post-title"><?php the_title(); ?></a></h3>

<?php endwhile; ?>