因此，事实证明，您实际上无法以这种方式将ACF/自定义字段添加到搜索查询中。这似乎迫使和进入了质疑。

我使用了多种来源的组合来创建下面的内容，现在效果非常好。

/* ADD META FIELD TO SEARCH QUERY */
// fields for Ajax search, admin and normal search
if (!isset($GLOBALS[\'current_screen\']) && !is_customize_preview()):
    // DAMN AJAX! is_admin() is always true when using it ;-/
    add_meta_field_to_search_query(\'loc_refid\');
        add_meta_field_to_search_query(\'location_postcode_preview\');
    add_meta_field_to_search_query(\'location_region\');
    add_meta_field_to_search_query(\'location_areas\');

elseif (is_admin()):
    add_meta_field_to_search_query(\'loc_refid\');
    add_meta_field_to_search_query(\'location_postcode\');
    add_meta_field_to_search_query(\'location_postcode_preview\');
    add_meta_field_to_search_query(\'location_region\');
    add_meta_field_to_search_query(\'location_areas\');
    add_meta_field_to_search_query(\'location_map_position\' );
    add_meta_field_to_search_query(\'user_organisation\');
    add_meta_field_to_search_query(\'user_position\');
    add_meta_field_to_search_query(\'client_location\');
    add_meta_field_to_search_query(\'user_email\');
else:
    add_meta_field_to_search_query(\'loc_refid\');           
    add_meta_field_to_search_query(\'location_postcode_preview\');
    add_meta_field_to_search_query(\'location_region\');
    add_meta_field_to_search_query(\'location_areas\');

endif;

function add_meta_field_to_search_query($field, $condition = "LIKE")
{
    // echo "add_meta_field_to_search_query; field:$field";

    if (isset($GLOBALS[\'added_meta_field_to_search_query\'])) {
        $GLOBALS[\'added_meta_field_to_search_query\'][] = \'\\\'\' . $field . \'\\\'\';
        return;
    }

    $GLOBALS[\'added_meta_field_to_search_query\']   = array();
    $GLOBALS[\'added_meta_field_to_search_query\'][] = \'\\\'\' . $field . \'\\\'\';

    add_filter(\'posts_join\', function ($join) {
        // echo "$s \'posts_join\' <br />";
        global $wpdb;
        if (is_search()) {
            $join .= " LEFT JOIN $wpdb->postmeta ON $wpdb->posts.ID = $wpdb->postmeta.post_id ";
        }
        return $join;
    });

    add_filter(\'posts_groupby\', function ($groupby) {
        // echo "$s \'posts_groupby\' <br />";
        global $wpdb;
        if (is_search()) {
            $groupby = "$wpdb->posts.ID";
        }
        return $groupby;
    });

    add_filter(\'posts_search\', function ($search_sql) {
        global $wpdb;

        $search_terms = get_query_var(\'search_terms\');

        if (!empty($search_terms)) {
            // echo "posts_search<br />";
            // print_r($search_terms);
            foreach ($search_terms as $search_term) {
                // echo "search_term: $search_term<br />";
                $old_or     = "OR ({$wpdb->posts}.post_content LIKE \'{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}\')";
                $new_or     = $old_or . " OR ({$wpdb->postmeta}.meta_value LIKE \'{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}\' AND {$wpdb->postmeta}.meta_key IN (" . implode(\', \', $GLOBALS[\'added_meta_field_to_search_query\']) . "))";
                $search_sql = str_replace($old_or, $new_or, $search_sql);
            }
        }

        $search_sql = str_replace(" ORDER BY ", " GROUP BY $wpdb->posts.ID ORDER BY ", $search_sql);

        return $search_sql;
    });

    // ajax seach only, basically same as above but checking for $GLOBALS[\'fd_search_term\'] which holds the search string
    add_filter(\'posts_where\', function ($search_sql) {
        global $wpdb;

        // print_r($wpdb);
        $search_terms = explode(\' \', $GLOBALS[\'fd_search_term\']);

        // if (!empty($search_terms) && !isset($GLOBALS[\'current_screen\']) && !is_customize_preview() && !is_search()) {

        if ($GLOBALS[\'fd_search_term\']) {
            // echo "AJAX posts_search<br />";
            // print_r($search_terms);
            foreach ($search_terms as $search_term) {
                // echo "search_term: $search_term<br />";
                $old_or     = "OR ({$wpdb->posts}.post_content LIKE \'{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}\')";
                $new_or     = $old_or . " OR ({$wpdb->postmeta}.meta_value LIKE \'{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}\' AND {$wpdb->postmeta}.meta_key IN (" . implode(\', \', $GLOBALS[\'added_meta_field_to_search_query\']) . "))";
                $search_sql = str_replace($old_or, $new_or, $search_sql);
            }
        }

        $search_sql = str_replace(" ORDER BY ", " GROUP BY $wpdb->posts.ID ORDER BY ", $search_sql);

        return $search_sql;
    });

}