/**
* Returns general cache key indenpendent on query parameters or sql limit
* Used e.g. for previously accessed columns caching
* @return string
*/
protected function getGeneralCacheKey()
{
if ($this->generalCacheKey) {
return $this->generalCacheKey;
}
return $this->generalCacheKey = md5(serialize(array(__CLASS__, $this->name, $this->sqlBuilder->getConditions())));
}