I was wondering what the recommended practice is for locating a child object within a parent using some property.

consider the following model fragment:


I would like to find a chilld of Parent p with a particular SomeClass ref
value.

I know I could go down the path of running a query and efficiently
retrieve the appropriate child, using a DAO etc.

However, some times it may be arguably part of the domain model interface to provide such access method in Parent:


especially if persistence is abstracted away.

This, of course leads to the n+1 query behaviour when iterating, causing
a significant penalty during runtime.

What are the recommended solutions for this problem that people out
there are using?

Don't forget the power of the querying abilities of hibernate. Write a simple HQL query to find the child you are after.

David,


I don't dispute the power of Hibernate and it certainly has it's place. What
I was after was more of a response to a 'poll' sort of thing where people
state which method they use.
Again, whilst Hibernate certainly allows me to find the right child in the
scenario I describe above very easily, it also moves a responsibility of
Parent to an external object, a DAO of some sort. And while this is A
Good Thing for performance reasons, it also means that an operation
that is part of my domain model is now somewhere else, and I wanted
peoples' opinion on this.

Understand your point. I use HQL mostly. There is nothing wrong with walking the domain class structure either just a risk (depending on the situation) that many SQLs could be generated in the process. This may or may not be OK - depends on the judgement of the developer et al.