Deletes all expired transients.
Description
Note that this function won’t do anything if an external object cache is in use.
The multi-table delete syntax is used to delete the transient record from table a, and the corresponding transient_timeout record from table b.
Parameters
$force_db
bool
Optional
Force cleanup to run against the database even when an external object cache is used.
Default: false
Source
File: wp-includes/option.php.
View all references
function delete_expired_transients( $force_db = false ) {
global $wpdb;
if ( ! $force_db && wp_using_ext_object_cache() ) {
return;
}
$wpdb->query(
$wpdb->prepare(
"DELETE a, b FROM {$wpdb->options} a, {$wpdb->options} b
WHERE a.option_name LIKE %s
AND a.option_name NOT LIKE %s
AND b.option_name = CONCAT( "_transient_timeout_", SUBSTRING( a.option_name, 12 ) )
AND b.option_value < %d",
$wpdb->esc_like( "_transient_" ) . "%",
$wpdb->esc_like( "_transient_timeout_" ) . "%",
time()
)
);
if ( ! is_multisite() ) {
// Single site stores site transients in the options table.
$wpdb->query(
$wpdb->prepare(
"DELETE a, b FROM {$wpdb->options} a, {$wpdb->options} b
WHERE a.option_name LIKE %s
AND a.option_name NOT LIKE %s
AND b.option_name = CONCAT( "_site_transient_timeout_", SUBSTRING( a.option_name, 17 ) )
AND b.option_value < %d",
$wpdb->esc_like( "_site_transient_" ) . "%",
$wpdb->esc_like( "_site_transient_timeout_" ) . "%",
time()
)
);
} elseif ( is_multisite() && is_main_site() && is_main_network() ) {
// Multisite stores site transients in the sitemeta table.
$wpdb->query(
$wpdb->prepare(
"DELETE a, b FROM {$wpdb->sitemeta} a, {$wpdb->sitemeta} b
WHERE a.meta_key LIKE %s
AND a.meta_key NOT LIKE %s
AND b.meta_key = CONCAT( "_site_transient_timeout_", SUBSTRING( a.meta_key, 17 ) )
AND b.meta_value < %d",
$wpdb->esc_like( "_site_transient_" ) . "%",
$wpdb->esc_like( "_site_transient_timeout_" ) . "%",
time()
)
);
}
}