我有一个搜索页面，如果主搜索返回0个结果，那么将使用以下查询。

代码为

$num_res = $wp_query->post_count;
$get_search_term = get_search_query();

if($num_res == 0)
{

    $args = array(
        \'post_type\'     => \'resources\',
        \'meta_key\'      => \'resource_txt\',
        \'meta_value\'    => $get_search_term,
        \'meta_compare\'  => \'LIKE\' );
    $custom_query =  new WP_Query( $args );
}

现在我得到一个错误"Not unique table/alias: \'wp_postmeta\'"

当我在浏览器中打印第二个查询时，它会说，

SELECT SQL_CALC_FOUND_ROWS 

DISTINCT wp_posts.ID FROM wp_posts 

INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id ) 

LEFT JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) 

WHERE 1=1 

AND ( ( wp_postmeta.meta_key = \'resource_txt\' AND CAST(wp_postmeta.meta_value AS CHAR) LIKE \'%insurance claim%\' ) ) 

AND wp_posts.post_type = \'resources\' 

AND (wp_posts.post_status = \'publish\' OR wp_posts.post_status = \'private\') 

GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 10

我必须关闭上一个查询，然后运行自定义查询。非常感谢您的帮助。

 <?php
function search_posts( $query ) {

    // Make sure this only runs on the main query on the front page
    if ($query->is_main_query() ) {

        // Exclude posts that have been explicitly set to hidden
        $query->set(\'meta_query\', array(
            \'relation\' => \'AND\',
            // Include posts where the meta key isn\'t set
            array(
                \'key\'     => \'resource_txt\',
                \'value\'   => $get_search_term, // A value must exist due to https://core.trac.wordpress.org/ticket/23268
                \'compare\' => \'LIKE\',
            ),
        ) );

    }

}
add_action( \'pre_get_posts\', \'search_posts\' );
?>