Sorting association data

herbert912 · **Joined:** Mon Jan 07, 2008 9:51 am **Posts:** 3

Hi.

I have two related objects, Account and LineItem. See end of this post for hibernate mapping data. In "view" type situations I would like to sort the LineItems associated with an account. I would like the user to control the column used for sorting so this sorting must be at run-time, preferably at the database.

I can succesfully sort LineItems at runtime using both HQL and Criteria, however I can only receive a new List of LineItems using this approach. I would like to receive the sorted data within the existing Object graph, that is as an updated collection in an Account object. Is this possible?

Code:

<class name="Account" table="FINANCE_ACCOUNTS"> 
    <id name="accountID"> 
        <generator class="increment"/>    
    </id> 
    <property name="name"/> 
    <property name="type" type="accountType"/> 
        
    <set name="lineItems"> 
      <key column="accountId"/> 
      <one-to-many class="LineItem"/> 
    </set> 
       
    <many-to-one name="user" column="userid"/>        
</class> 
<class name="LineItem" table="FINANCE_LINEITEM"> 
    <id name="lineItemId"> 
        <generator class="increment"/>          
    </id> 
    <property name="description"/> 
    <property name="amount"/> 
    <property name="postingDate"/> 
       
    <many-to-one name="account" column="accountId"/> 
</class>    

Many thanks for any help given.

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

herbert912,

Your question implies that you are providing some kind of "sorting" feature by using a "disconnected" new collection of children each time.
I advise you not to do that. Issue a new HQL or Criteria instead, with the new sorting. Provided you keep your resultsets reasonably short, let Hibernate and the database do the work, and don't be worrying about whether or not your reshuffled collection will be persisted in an undesirable way.

herbert912 · **Joined:** Mon Jan 07, 2008 9:51 am **Posts:** 3

Hi Gonzalo.

Thanks for the response. I perhaps didnt explain my question clearly so let me clarify. So basically I want to retrieve a complete object graph ie Account with associated LineItems as a collection which I will disconnect to pass to the presentation tier. I would like the ability to specify (at runtime) the sorting on the associated LineItems within that graph. I do not want to receive just a collection containing LineItems.

Thanks for your help.

nvintila · **Joined:** Wed Mar 15, 2006 8:10 pm **Posts:** 2

Does this help?

http://www.hibernate.org/hib_docs/annot ... /Sort.html

Nick

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

So if you already made the design decision to pass a disconnected collection to the presentation tier, (that is, not belonging to the object graph) I don't know what your Hibernate-related question is.