You should adapt it to fit your needs, e.g. (not tested) :
//创建一个新的筛选函数，将where子句添加到查询中

function filter_where( $where = \'\' ) {
   $where .= " AND post_date > \'" . date(\'Y-m-d\', strtotime(\'-1 year\')) . "\'";
return $where;
}<br>

add_filter( \'posts_where\', \'filter_where\' );
$query = new WP_Query( $query_string );<br>
remove_filter( \'posts_where\', \'filter_where\' );