Question

An application I’m working on does all its queries by identifier using session.load(). Given the chaos it causes when it can’t find the identifier and throws an exception, I’m thinking of swapping it over to session.get(). But before I do that, it’s such a fundamental part of the system that I want to make sure there’s absolutely no other difference between the two methods. Is there any reason you can think of why the original developers would have chosen load() over get() aside from the handling of invalid IDs?

EDIT: As stated above, I’m fully aware that get returns false and load throws an exception. I’m asking if there’s any OTHER way that they differ.

Answer 1

Isn’t it so that Get never returns a proxy whereas Load does ?

http://ayende.com/Blog/archive/2009/04/30/nhibernate-ndash-the-difference-between-get-load-and-querying-by.aspx

I think that this is important:

Why is this useful? Well, if you know
that the value exist in the database,
and you don’t want to pay the extra
select to have that, but you want to
get that value so we can add that
reference to an object, you can use
Load to do so:
The code above will not result in a
select to the database, but when we
commit the transaction, we will set
the CustomerID column to 1. This is
how NHibernate maintain the OO facade
when giving you the same optimization
benefits of working directly with the
low level API.

From the NH 2.0 ref documentation:

Note that Load() will throw an
unrecoverable exception if there is no
matching database row. If the class is
mapped with a proxy, Load() returns an
object that is an uninitialized proxy
and does not actually hit the database
until you invoke a method of the
object. This behaviour is very useful
if you wish to create an association
to an object without actually loading
it from the database.

If you are not certain that a matching
row exists, you should use the Get()
method, which hits the database
immediately and returns null if there
is no matching row.