Theodore, thank you for the response.
I may probably have not specified requirements clearly, I understand that Hibernate can load related entries from another table into a list of objects of another type, in my case it would be Customer containing a set of CustomerDetails.
But I want only one object Customer to be loaded from/to different tables Customer/CustomerDetail which have the same primary key id. Basically Customer and CustomerDetails is the one table splitted into two, relation between tables is 1-1. So for one particular Customer object it would load properties "id" and "name" from table Customer and "comments" from CustomerDetails.
As for now, we come to solution when CustomerDetails is loaded as a separate object, but its propertly "comments" is exposed by delegate method in Customer class.