Piwik\Plugins\UsersManager\Model::deleteUserAccess PHP Method

    public function deleteUserAccess($userLogin, $idSites = null)
    {
        $db = $this->getDb();
        if (is_null($idSites)) {
            $db->query("DELETE FROM " . Common::prefixTable("access") . " WHERE login = ?", array($userLogin));
        } else {
            foreach ($idSites as $idsite) {
                $db->query("DELETE FROM " . Common::prefixTable("access") . " WHERE idsite = ? AND login = ?", array($idsite, $userLogin));
            }
        }
    }

 /**
  * Set an access level to a given user for a list of websites ID.
  *
  * If access = 'noaccess' the current access (if any) will be deleted.
  * If access = 'view' or 'admin' the current access level is deleted and updated with the new value.
  *
  * @param string $userLogin The user login
  * @param string $access Access to grant. Must have one of the following value : noaccess, view, admin
  * @param int|array $idSites The array of idSites on which to apply the access level for the user.
  *       If the value is "all" then we apply the access level to all the websites ID for which the current authentificated user has an 'admin' access.
  *
  * @throws Exception if the user doesn't exist
  * @throws Exception if the access parameter doesn't have a correct value
  * @throws Exception if any of the given website ID doesn't exist
  *
  * @return bool true on success
  */
 public function setUserAccess($userLogin, $access, $idSites)
 {
     $this->checkAccessType($access);
     $this->checkUserExists($userLogin);
     $this->checkUserHasNotSuperUserAccess($userLogin);
     if ($userLogin == 'anonymous' && $access == 'admin') {
         throw new Exception(Piwik::translate("UsersManager_ExceptionAdminAnonymous"));
     }
     // in case idSites is all we grant access to all the websites on which the current connected user has an 'admin' access
     if ($idSites === 'all') {
         $idSites = \Piwik\Plugins\SitesManager\API::getInstance()->getSitesIdWithAdminAccess();
     } else {
         $idSites = Site::getIdSitesFromIdSitesString($idSites);
     }
     if (empty($idSites)) {
         throw new Exception('Specify at least one website ID in &idSites=');
     }
     // it is possible to set user access on websites only for the websites admin
     // basically an admin can give the view or the admin access to any user for the websites he manages
     Piwik::checkUserHasAdminAccess($idSites);
     $this->model->deleteUserAccess($userLogin, $idSites);
     // if the access is noaccess then we don't save it as this is the default value
     // when no access are specified
     if ($access != 'noaccess') {
         $this->model->addUserAccess($userLogin, $access, $idSites);
     } else {
         if (!empty($idSites) && !is_array($idSites)) {
             $idSites = array($idSites);
         }
         Piwik::postEvent('UsersManager.removeSiteAccess', array($userLogin, $idSites));
     }
     // we reload the access list which doesn't yet take in consideration this new user access
     Access::getInstance()->reloadAccess();
     Cache::deleteTrackerCache();
 }