AliasedQuery::getAliasName

public function getAliasName($alias)
{
	if (!isset($this->aliases[$alias]))
	{
		return null;
	}

	$field = $this->aliases[$alias];

	if (is_string($field))
	{
		return $field; // name
	}
	elseif (is_array($field)) // TODO Field support
	{
		$name = '__'.$alias.'_ALIAS__';
		$field['registered'] ??= false;
		if (!$field['registered'])
		{
			$field['registered'] = true;
			$this->registerRuntimeField($name, $field);
		}

		return $name;
	}

	throw new SystemException("invalid alias '$alias' type", 0, __FILE__, __LINE__);
}