I have a scenario, in which I want to load my associated object only once for many other objects. For Example,

I have following kind of code in my hbm file.

<class name="Account" table="Account" lazy="false"
polymorphism="explicit">

<composite-id name="key" class="AccountCompositePKey">
<key-property name="id" column="id"></key-property>
<key-property name="isSavingAccount"></key-property>
</composite-id>
<property name="accountId" />
<property name="accountName" />
.
.
.
<many-to-one name="user"
class="User" lazy="false"
column="createdBy"
not-null="true"
update="false"
insert="false"
unique="true"
outer-join="true"
property-ref="alias" />

</class>


In above example code, when ever Multiple accounts are fetched, then for every account a user object is loaded, even though user is same for all accounts. Meaning, for each account query hit, associated user is fetched.

What I want is to load user only once if he has more than one account in his name. For example, if user 1 has Accounts A, B, C, D in his name - then user 1 details should be loaded only once, even though all 4 accounts details are loaded.

Any one who has faced such issue and has found a solution, please advice me in achieving this.

Thanks in advance.

In that case, you should fetch the user first and get the accounts for the particular user. You could use a collection of accounts in the user entity. So everytime you load a single user, you will load all the accounts associated.

But if you say you have to fetch the accounts and then the user, then you cannot do it. There will be multible DB hits for the user.

I appreciate your response. It was a good food for thought. But, Unfortunately, it does not resolves my problem.

The design is such that, I am searching for all accounts in my application. Now, each account has a "createdBy" field, which is basically references to User name.

When I put no search criteria, then due to many-to-one association in the above code example, each account record fetch will associate a user record with it. I desire do something that fetches user record only once for all the account records having reference to that user. No matter, if any other method of association mapping requires to be used in the hbm file.

This is basically a performance issue.

hi,

you could try implementing a second level cache strategy somehow although I'm not really sure how this can be applied to a many-to-one association.


cheers