For performance reasons, I set up all of my value objects with primary keys to handle the key definition as well as the 1..* relationships within the value objects. We had just waaaaaaay too much data coming back and lazy loading was out of the question. Anyway, I'm not completely sure how to map the key into the vo with the hbm. Also, when I do a load with the session, do I just pass in the key or do I need to do something else? Thanks in advance.

Here's my hbm file, key class, vo, and dao.

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="com.tab.core.shared.vo.Debtor" table="Debtor">
<id name="key" type="com.tab.core.shared.vo.DebtorPK" column="debtor_id">
<generator class="assigned"/>
</id>
<property name="comment" column="comment" type="string"/>
<property name="numInvoices" column="no_inv" type="integer"/>
<property name="state" column="state" type="string"/>
<property name="sic" column="sic" type="string"/>
<property name="phone" column="tele" type="string"/>
<property name="street2" column="street2" type="string"/>
<property name="street1" column="street1" type="string"/>
<property name="duns" column="duns" type="string"/>
<property name="averagePay" column="avg_pay" type="double"/>
<property name="status" column="status" type="string"/>
<property name="country" column="country" type="string"/>
<property name="city" column="city" type="string"/>
<property name="contact" column="contact" type="string"/>
<property name="creditLimit" column="credit_lim" type="double"/>
<property name="zip" column="zip" type="string"/>
<property name="fax" column="fax" type="string"/>
<property name="name2" column="name2" type="string"/>
<property name="contactPhone" column="c_tele" type="string"/>
<property name="name" column="name1" type="string"/>
</class>
</hibernate-mapping>



*********************************************************
Here's the Key class

public final class DebtorPK extends CacheableKey implements Serializable
{
private String debtorId;

public DebtorPK()
{
setControllerClass("DebtorDAO.class");
setDependentClass(Debtor.class);
}

public DebtorPK(final String debtorId)
{
this();
this.debtorId = debtorId;
}

public String getDebtorId()
{
return debtorId;
}

public void setDebtorId(final String debtorId)
{
this.debtorId = debtorId;
}
}

************************************************************
The value object is just the standard getters/setters.

************************************************************
Here's a snipped out of the HibernateDAO

public final MutableVO findByPrimaryKey(Key obj) throws Exception
{
Session session = getSession();
MutableVO retVal = (MutableVO)session.load(obj.getDependentClass(), obj);
closeSession(session);
return retVal;
}

Well, I found an example like this. I'll try this when I get to work and see if this is the way to do it.


<id name="key" type="com.tab.core.shared.vo.DebtorPK" >
<key-property name="debtorId" type="string" column="debtor_id"/>
</id>

That is not a valid mapping. <key-property> is a subelement of <composite-id>, not <id>.

How do I map the primary key column(s) to the key class? I am probably missing some good examples. Do you know of any or can you give me a way to do this properly?

Thanks

Perhaps you just wish to use the standard "custom identifier type" pattern from the wiki?

I'll check it out. Sorry if this is a question that has been answered before. I am new to hibernate and I really would like to use it instead of the straight jdbc I am currently using. Thanks for the help.

As outlined in the documentation, you could utilize a component composite key.


Check out the section on this usage, as there are a lot of considerations to tis type of implementation.
http://www.hibernate.org/hib_docs/reference/html/components.html#components-s2-3

Or what steve said ;)

Either one should work.

I think you hit the nail on the head with the composite identifier. That looks like exactly what I was looking for. I must have missed it when I was reading through all the docs. I will give it a try on monday when I get in to work. Thanks for all the help. I'll be back if I get messed up again... DOH!!

I think the custom identifier will work well with some of the legacy conversions we have to make. We tap into some old databases that stored dates as integers and other weird items like that. We currently convert them as we pull them out of the database so the programmer knows the correct datatype they are dealing with. The database names aren't always intuitive enough to know that an int is really a date among other things unless you are familiar with the system. As for the keys, I think it might be hard to write identifiers for all of my keys. Thats extra work I'm trying to avoid. I'll most likely go the composite identifer or composite key approach for my primary key classes and the custom identifier for the other type conversions I need to do. The more I'm learning about hibernate, the more I like it. I didn't realize just how flexible it is. Thanks.

Hmmmm... I think I got a bit confused again. Is there anything like the custom identifier that I can use to do type conversions on the property of a value object? Seems they used ints for everything in one of the databases. I need to convert some ints to Dates, int to Double, and some others. Is this possible?

Sure. This is a typical use case for a UserType.

I have some primary key fields in the database that are serial type. How can I map these to my composite-id? Here's what a sample mapping file of mine looks like. The addendem_id is a serial type in the database. When I try to do an insert, I get an error saying the primary key field is null.

Thanks in advance.

Nic


<hibernate-mapping>
<!-- com.tab.core.shared.vo.MC_AchAddendem root -->
<class name="com.tab.core.shared.vo.MC_AchAddendem" table="ach_addendem">
<composite-id name="key" class="com.tab.core.shared.vo.MC_AchAddendemPK">
<key-property name="id" column="addendem_id" type="integer"/>
</composite-id>
<property name="sequenceNumber" column="sequence_num" type="integer"/>
<component name="returnCode" class="com.tab.core.shared.vo.MC_AchReturnCodePK">
<property name="returnCode" column="return_code" type="string"/>
</component>
<component name="achTransaction" class="com.tab.core.shared.vo.MC_AchTransactionPK">
<property name="achId" column="ach_id" type="integer"/>
</component>
<property name="data" column="data" type="string"/>
</class>
</hibernate-mapping>

I have some primary key fields in the database that are serial type. How can I map these to my composite-id? Here's what a sample mapping file of mine looks like. The addendem_id is a serial type in the database. When I try to do an insert, I get an error saying the primary key field is null.

Thanks in advance.

Nic


<hibernate-mapping>
<!-- com.tab.core.shared.vo.MC_AchAddendem root -->
<class name="com.tab.core.shared.vo.MC_AchAddendem" table="ach_addendem">
<composite-id name="key" class="com.tab.core.shared.vo.MC_AchAddendemPK">
<key-property name="id" column="addendem_id" type="integer"/>
</composite-id>
<property name="sequenceNumber" column="sequence_num" type="integer"/>
<component name="returnCode" class="com.tab.core.shared.vo.MC_AchReturnCodePK">
<property name="returnCode" column="return_code" type="string"/>
</component>
<component name="achTransaction" class="com.tab.core.shared.vo.MC_AchTransactionPK">
<property name="achId" column="ach_id" type="integer"/>
</component>
<property name="data" column="data" type="string"/>
</class>
</hibernate-mapping>

From reading your old forum, it looks like you were going to allow a generator element to be placed within the <composite-id> tag. Is this still coming? Is this what I need?

Thanks