/**
* Returns the alias for the root class in the EPQ_N_FROM node
* (Also set the root class)
* @return false|string
* @throws epExceptionQueryBuilder
*/
private function _rootAlias()
{
// get from node
if (!($from = $this->root->getChild('from'))) {
throw new epExceptionQueryBuilder($this->_e("Cannot found 'from' clause"));
return false;
}
// get from items
if (!($items = $from->getChildren())) {
throw new epExceptionQueryBuilder($this->_e("No from items specified"));
return false;
}
// go through each item
$isRoot = true;
foreach ($items as &$item) {
// get class name
$class = $item->getParam('class');
// get class map
if (!($cm = $this->em->getClassMap($class))) {
throw new epExceptionQueryBuilder($this->_e("No class map for class [" . $class . "]"));
continue;
}
// does it have param 'alias' set?
if (!($alias = $item->getParam('alias'))) {
$alias = $this->generateAlias($class);
}
// put it into aliases array
$this->aliases[$alias] = $class;
// set up root class
if ($isRoot) {
$isRoot = false;
$this->root_alias = $alias;
$this->root_class = $class;
$this->root_cms[] = $cm;
// get the db for the class
if (!($this->db = $this->em->getDb($class, $cm))) {
throw new epExceptionQueryBuilder($this->_e("Cannot found db for root class [" . $class . "]"));
continue;
}
$this->root_classes[] = $cm->getName();
// combine all the children and the root class, so we can
// get results for all children
$rootClasses = $cm->getChildren(true);
foreach ($rootClasses as $rootCm) {
$this->root_classes[] = $rootCm->getName();
$this->root_cms[] = $rootCm;
}
}
}
// if not generate one
return $this->root_alias;
}
