code: public final function uninstall() {
  		if (!App::db()->select('id')->from('{module}')->where(['name' => $this->namespace])->exist('id')) {
  			return false;
  		}
  		$rst = $this->onUninstall();
  		if ($rst) {
  			$db     = App::db();
  			$tables = $this->getDefinedTables($db->getDialect());
  			if ($tables ['tables']) {
  				foreach ($tables ['tables'] as $table) {
  					$db->exec('DROP TABLE IF EXISTS ' . $table);
  				}
  			}
  			if ($tables ['views']) {
  				foreach ($tables ['views'] as $table) {
  					$db->exec('DROP VIEW IF EXISTS ' . $table);
  				}
  			}
  			$db->delete()->from('{module}')->where(['name' => $this->namespace])->exec();
  			App::cfg();
  		}
  
  		return $rst;
  	}
docs: 卸载.
  @return bool
  @throws