Hi,

I am trying to find solution and approach for a common task in my projects.
I have a class and I want to use a mapping file to fill the properties of this class.
Also, I have a table which stores the data for this class. And I have a foreign key in this table that points to onother table.

How can i use hibernate-mapping file to map all the fields from my table and one field from the table where the foreign key points?

Thank you in advance,
Best, Daniel

Do you mean have a method of automatically populate the Java class based on an already written hibernate mapping file? If this is your question, you can use Hibernate tools, that integrates with Eclipse.

As far as I understand your second question, read the documentation:

http://www.hibernate.org/hib_docs/reference/en/html/example-mappings.html
http://www.hibernate.org/hib_docs/v3/reference/en/html/tutorial.html#tutorial-associations
http://www.hibernate.org/hib_docs/v3/reference/en/html/tutorial.html#tutorial-associations

I can give a concrete situation that illustrate the problem.
It's not about eclipse tools, it's more likely about writing a hibernate mapping file!

I have a table PAYMENT and another table PAYMENT_STATUS
In table payment I have a foreign key PAYMENT_STATUS_ID.

I have only one class Payment. And I use HQL and hibernate mapping file
to map all the fields from the PAYMENT table to the Payment class.
...("from Payment");

It maps all the table fields to the class Person
And it works fine, but!

But I can't show the user the PAYMENT_STATUS_ID field. This is an Integer field ant does not make any sanse to the user. But I have only this property in Payment. I want to show the user the name of the Status.
This status is in the second table - PAYMENT_STATUS.NAME.

I tought that the simplest solution will be to write one more property in the hibernate mapping file (Payment.hbm.xml). And in this property tag to say that this is a column from another table, and the foreign key is ...!
And it should look something like that
<property name="statusText" table="PAYMENT_STATUS" key="STATUS_ID" column="STATUS_TEXT" />

and this will cause a join between these 2 tables on the field STATUS_ID
and return of the STATUS_TEXT column

I don't want to have extra class for my second table.
Also I don't want to use formula in my property tag

Tanks for the reply, wild_oscar!

Best, Daniel

error

error

I believe this is what you're looking for:
http://www.thearcmind.com/confluence/display/RandomThoughts/Hibernate+need+to+access+properties+on+join+table

I don't think it's recommended, though, as I suspect you'll get into problems if you update the values from your STATUS_TEXT column...

Tell us if it works.

PS: If you feel my answer was useful, please rate the answer. Thanks![/url]

Basically, what you're looking for is a subselect on your Payment class, where you'll have to select all the Payment table properties and the status_text from your inner joined class:

Dear, wild_oscar!

The solution you gave me exactly matches my problem.
Thank you very much!

I don't need to update the field from the other table so it works perfect to me.

Here is the code in the mapping file:

<hibernate-mapping schema="dbo" package="data">
<class name="Payment" table="PAYMENT" schema="dbo"
optimistic-lock="none">

<subselect>
select
p.*,
s.NAME as STATUS_TEXT
from PAYMENT p
inner join
PAYMENT_STATUS s on s.STATUS_ID=p.STATUS_ID
</subselect>

<id name="paymentId" type="integer" unsaved-value="null">
<column name="PAYMENT_ID" not-null="true" unique="true"
index="PK_PAYMENT" />
<generator class="sequence">
<param name="sequence">SEQ_PAYMENT</param>
</generator>

</id>
<property name="statusId" type="long" column="STATUS_ID" />
<property name="statusText" column="STATUS_TEXT" insert="false" update="false"/>

</class>
</hibernate-mapping>

Could you please rate my answers so I can earn credits in the forum? Thank you.