4.6.x bootstrap.inc cache_clear_all($cid = NULL, $wildcard = false)
4.7.x bootstrap.inc cache_clear_all($cid = NULL, $wildcard = false)
5.x cache.inc cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE)
6.x cache.inc cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE)
6.x cache-install.inc cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE)
7.x cache.inc cache_clear_all($cid = NULL, $bin = NULL, $wildcard = FALSE)

Expire data from the cache. If called without arguments, expirable entries will be cleared from the cache_page and cache_block tables.


$cid: If set, the cache ID to delete. Otherwise, all cache entries that can expire are deleted.

$table: If set, the table $table to delete from. Mandatory argument if $cid is set.

$wildcard: If $wildcard is TRUE, cache IDs starting with $cid are deleted in addition to the exact cache ID specified by $cid. If $wildcard is TRUE and $cid is '*' then the entire table $table is emptied.

51 calls to cache_clear_all()
block_add_block_form_submit in modules/block/block.admin.inc
Save the new custom block.
block_admin_configure_submit in modules/block/block.admin.inc
block_admin_display_form_submit in modules/block/block.admin.inc
Process main blocks administration form submission.
block_box_delete_submit in modules/block/block.admin.inc
Deletion of custom blocks.
comment_admin_overview_submit in modules/comment/comment.admin.inc
Process comment_admin_overview form submissions.

... See full list


includes/cache.inc, line 136


function cache_clear_all($cid = NULL, $table = NULL, $wildcard = FALSE) {
  global $user;
  if (!isset($cid) && !isset($table)) {

    // Clear the block cache first, so stale data will
    // not end up in the page cache.
    cache_clear_all(NULL, 'cache_block');
    cache_clear_all(NULL, 'cache_page');
  if (empty($cid)) {
    if (variable_get('cache_lifetime', 0)) {

      // We store the time in the current user's $user->cache variable which
      // will be saved into the sessions table by sess_write(). We then
      // simulate that the cache was flushed for this user by not returning
      // cached data that was cached before the timestamp.
      $user->cache = time();
      $cache_flush = variable_get('cache_flush_' . $table, 0);
      if ($cache_flush == 0) {

        // This is the first request to clear the cache, start a timer.
        variable_set('cache_flush_' . $table, time());
      else {
        if (time() > $cache_flush + variable_get('cache_lifetime', 0)) {

          // Clear the cache for everyone, cache_lifetime seconds have
          // passed since the first request to clear the cache.
          db_query("DELETE FROM {" . $table . "} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, time());
          variable_set('cache_flush_' . $table, 0);
    else {

      // No minimum cache lifetime, flush all temporary cache entries now.
      db_query("DELETE FROM {" . $table . "} WHERE expire != %d AND expire < %d", CACHE_PERMANENT, time());
  else {
    if ($wildcard) {
      if ($cid == '*') {
        db_query("TRUNCATE TABLE {" . $table . "}");
      else {
        db_query("DELETE FROM {" . $table . "} WHERE cid LIKE '%s%%'", $cid);
    else {
      db_query("DELETE FROM {" . $table . "} WHERE cid = '%s'", $cid);


hedinfoto’s picture

Has anyone seen the cache_form table get huge? Ours was 445mb!

I hade to manually run cache_clear_all(NULL, 'cache_form'); then optimise the table form mysql to clear it out.

graytoby’s picture

Yes, I've noticed it a few times. I always empty it. I wonder why clearing all caches doesn't empty that table. Perhaps a bug in core?

dunx’s picture

I had an issue clearing nodecomments data from cache_view_data when calling cache_clear_all('nodecomments:','cache_view_data',TRUE)

It wasn't clearing the cache. The ":" colon was the problem. I took that off and it works fine.

Uv516’s picture

I wonder if cache_clear_all will respect $db_prefix. It seems that it doesn't.
All my tables are named main_ as prefix. Shouldn't cache_clear_all have a procedure for inserting the $db_prefix before call to db_query?