The getarchives_join WordPress PHP filter allows you to modify the SQL JOIN clause for retrieving archives.
Usage
add_filter('getarchives_join', 'my_custom_getarchives_join', 10, 2);
function my_custom_getarchives_join($sql_join, $parsed_args) {
// your custom code here
return $sql_join;
}
Parameters
$sql_join(string) – Portion of the SQL query containing the JOIN clause.$parsed_args(array) – An array of default arguments.
More information
See WordPress Developer Resources: getarchives_join
Examples
Change JOIN clause to include a custom table
Modify the SQL JOIN clause to include a custom table called “my_custom_table”.
add_filter('getarchives_join', 'add_custom_table_to_getarchives_join', 10, 2);
function add_custom_table_to_getarchives_join($sql_join, $parsed_args) {
global $wpdb;
$sql_join .= " LEFT JOIN {$wpdb->prefix}my_custom_table ON {$wpdb->prefix}my_custom_table.post_id = {$wpdb->prefix}posts.ID";
return $sql_join;
}
Include only posts with a specific meta key
Modify the SQL JOIN clause to include only posts with a specific meta key “featured”.
add_filter('getarchives_join', 'filter_archives_by_meta_key', 10, 2);
function filter_archives_by_meta_key($sql_join, $parsed_args) {
global $wpdb;
$sql_join .= " INNER JOIN {$wpdb->postmeta} ON {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id AND {$wpdb->postmeta}.meta_key = 'featured'";
return $sql_join;
}
Include only posts from specific categories
Modify the SQL JOIN clause to include only posts from specific categories (e.g., 2 and 5).
add_filter('getarchives_join', 'filter_archives_by_categories', 10, 2);
function filter_archives_by_categories($sql_join, $parsed_args) {
global $wpdb;
$sql_join .= " INNER JOIN {$wpdb->term_relationships} ON {$wpdb->posts}.ID = {$wpdb->term_relationships}.object_id";
$sql_join .= " INNER JOIN {$wpdb->term_taxonomy} ON {$wpdb->term_relationships}.term_taxonomy_id = {$wpdb->term_taxonomy}.term_taxonomy_id";
$sql_join .= " AND {$wpdb->term_taxonomy}.taxonomy = 'category' AND {$wpdb->term_taxonomy}.term_id IN (2, 5)";
return $sql_join;
}
Exclude posts from specific authors
Modify the SQL JOIN clause to exclude posts from specific authors (e.g., 3 and 7).
add_filter('getarchives_join', 'exclude_archives_by_authors', 10, 2);
function exclude_archives_by_authors($sql_join, $parsed_args) {
global $wpdb;
$sql_join .= " LEFT JOIN {$wpdb->users} ON {$wpdb->posts}.post_author = {$wpdb->users}.ID";
$sql_join .= " AND {$wpdb->users}.ID NOT IN (3, 7)";
return $sql_join;
}
Include only posts with a specific tag
Modify the SQL JOIN clause to include only posts with a specific tag “featured-tag”.
add_filter('getarchives_join', 'filter_archives_by_tag', 10, 2);
function filter_archives_by_tag($sql_join, $parsed_args) {
global $wpdb; $sql_join .= " INNER JOIN {$wpdb->term_relationships} ON {$wpdb->posts}.ID = {$wpdb->term_relationships}.object_id";
$sql_join .= " INNER JOIN {$wpdb->term_taxonomy} ON {$wpdb->term_relationships}.term_taxonomy_id = {$wpdb->term_taxonomy}.term_taxonomy_id";
$sql_join .= " INNER JOIN {$wpdb->terms} ON {$wpdb->term_taxonomy}.term_id = {$wpdb->terms}.term_id";
$sql_join .= " AND {$wpdb->term_taxonomy}.taxonomy = 'post_tag' AND {$wpdb->terms}.slug = 'featured-tag'";
return $sql_join;
}