php - 如何修改 wordpress 搜索以查询分类术语和类别术语？

Question

我想修改搜索，所以如果说我有一个名为“作者”的分类法并在帖子中添加了“Ian Rankin”一词，如果我搜索“Ian Rankin”，我希望该帖子出现。我想目前它只搜索标题和内容。 我怎样才能让它也成为搜索词？

Answer 1

You can alter the search query using filter hooks to join the taxonomy tables.

e.g. to also search on the 'author' taxonomy

First join the taxonomy tables

function tax_search_join( $join )
{
  global $wpdb;
  if( is_search() )
  {
    $join .= "
        INNER JOIN
          {$wpdb->term_relationships} ON {$wpdb->posts}.ID = {$wpdb->term_relationships}.object_id
        INNER JOIN
          {$wpdb->term_taxonomy} ON {$wpdb->term_taxonomy}.term_taxonomy_id = {$wpdb->term_relationships}.term_taxonomy_id
        INNER JOIN
          {$wpdb->terms} ON {$wpdb->terms}.term_id = {$wpdb->term_taxonomy}.term_id
      ";
  }
  return $join;
}
add_filter('posts_join', 'tax_search_join');

then find the search term in the taxonomy 'author'

function tax_search_where( $where )
{
  global $wpdb;
  if( is_search() )
  {
    // add the search term to the query
    $where .= " OR
    (
      {$wpdb->term_taxonomy}.taxonomy LIKE 'author'
      AND
      {$wpdb->terms}.name LIKE ('%".$wpdb->escape( get_query_var('s') )."%')
    ) ";
  }
  return $where;
}
add_filter('posts_where', 'tax_search_where');

and finally group the results by post id to avoid duplicate results because of the join

function tax_search_groupby( $groupby )
{
  global $wpdb;
  if( is_search() )
  {
    $groupby = "{$wpdb->posts}.ID";
  }
  return $groupby;
}
add_filter('posts_groupby', 'tax_search_groupby');

Answer 2

也可以通过使用 MySQL 的EXISTS函数和将term_relationships与terms连接起来的子查询来完成。我创建了以下代码段并将其放入functions.php中。这至少适用于 WordPress 版本 5.3.1：

// Search titles and tags
function and_extend_search( $search, &$wp_query ) {

    global $wpdb;

    if ( empty( $search ))
        return $search;

    $terms = $wp_query->query_vars[ 's' ];
    $exploded = explode( ' ', $terms );
    if( $exploded === FALSE || count( $exploded ) == 0 )
        $exploded = array( 0 => $terms );

    $search = '';
    
    foreach( $exploded as $tag ) {
        $search .= " AND (
            ($wpdb->posts.post_title LIKE '%$tag%')

            OR EXISTS
            (
                SELECT 
                    *
                FROM 
                    $wpdb->term_relationships 
                LEFT JOIN 
                    $wpdb->terms 
                ON 
                    $wpdb->term_relationships.term_taxonomy_id = $wpdb->terms.term_id
                WHERE
                        $wpdb->terms.name LIKE '%$tag%'
                    AND
                        $wpdb->term_relationships.object_id = $wpdb->posts.ID
            )
        )";
    }

    return $search;
}
add_filter('posts_search', 'and_extend_search', 500, 2);