POJO generation from DB, foreign keys

preddy98 · **Joined:** Thu Mar 15, 2007 2:53 pm **Posts:** 9

I am generating POJOs with ant script from DB.

I want to generate my foreign key references as scalar types.

For example:

User to UserStatus

I want to have my User POJO object to have

setUserStatusId(Long) instead of setUserStatus(UserStatus).

Looks like something like this is possible in eclipse with "Generate basic typed composite ids" field.

Does any one know how I can control this using ant build.xml or one of the properties files.

Thanks
Paddy

Ananasi · **Posted:** Thu Mar 15, 2007 3:50 pm

You might be able to do that in the hibernate.reveng.xml file. Try

Code:

...
  <table name="USER">
    <foreign-key constraint-name="FK_USER_USERSTATUS" foreign-table="USER_STATUS">
      <many-to-one exclude="true"/>
      <set exclude="true"/>
    </foreign-key>
  </table>
...

preddy98 · **Joined:** Thu Mar 15, 2007 2:53 pm **Posts:** 9

That doesn't do it. It stll generating a member variable UserStatus.

like

private UserStatus userStatusByUserStatusId;

along with getter and setters.

Thanks

stefanm · **Posted:** Mon Mar 19, 2007 8:17 am

annanasi should be right, but the <set exclude="true"/> is not really necessary here as you have a n:1 relation.
But see the Hibernate Tools 3.2.0beta9 documentation for more details on this (esp. chapter 5.2.4.3 <foreign key>

Of course you have to make sure that your hibernate.reveng.xml file is used.
So in your ant script, you must have something like this (note the revengfile attribute):

Code:

<jdbcconfiguration configurationfile=".\hibernate-hbm2java.cfg.xml"
             packagename="${dir.gensrc.package}"
             revengfile="hibernate.reveng.xml"
             detectmanytomany="false"
             >

max · **Posted:** Mon Mar 19, 2007 11:20 am

don't get why you would ever want this, but you could write a custom MetaDataDialect that returns zero foreignkeys for the tables you don't want references in the objectmodel.

preddy98 · **Joined:** Thu Mar 15, 2007 2:53 pm **Posts:** 9

Thanks Max. That helps.

I want our pojos to be simple value objects. I don't like them to be doing what's otherwise handled by DB and application transactional code such as referential integrigy, constraint management etc.,

Thanks again

rszabi · **Posted:** Thu Apr 05, 2007 5:16 am

Hi preddy98!
Can You tell me how have You finally resolved?

I want to be generated just a simple POJO without foreign keys mapping. (Oracle)

I make the generation with Ant.
So my code looks like:

Code:

        <hibernatetool destdir="${project.src}">
            <jdbcconfiguration
                    configurationfile="${project.etc}\hibernate.cfg.xml"
                    revengfile="${project.etc}\hibernate.reveng.xml"
                    packagename="${package.name}"
                    reversestrategy="org.hibernate.cfg.reveng.DelegatingReverseEngineeringStrategy"
                    detectmanytomany="false">
            </jdbcconfiguration>
            <hbm2java jdk5="${hibernate.jdk5}" ejb3="false"/>
        </hibernatetool>

..and the taskdef:

Code:

    <taskdef name="hibernatetool"
             classname="org.hibernate.tool.ant.HibernateToolTask"
             classpathref="toolslib"/>

But it seems to not work.
So I still have in pojo the Set-s at foreign keys.

Or have You writted your own class which implements MetaDataDialect?
Or this can made by changing the reverse engineering strategy?

max · **Posted:** Sat Apr 07, 2007 3:31 am

you need to customize the metadialect to lie by not returning in foreignkey info.

rszabi · **Posted:** Tue Apr 10, 2007 5:33 am

I can implement the MetaDataDialect in a class(MyMetaDataDialect), but where must I use that class?
How can I set to hibernatetool, or jdbconfiguration to use that class?
As I writted a little bit upper, there are two customizable classes which are now used, the reversestrategy as org.hibernate.cfg.reveng.DelegatingReverseEngineeringStrategy
and maybe in the hibernate.cfg.xml the
<property name="dialect">org.hibernate.dialect.OracleDialect</property>.

Or exists a property which takes a customized MetaDataDialect?

max · **Posted:** Tue Apr 10, 2007 5:58 am

http://www.hibernate.org/hib_docs/tools ... e/#d0e1781

hibernatetool.metadatadialect

rszabi · **Posted:** Tue Apr 10, 2007 10:16 am

Thank You Max!

(I have searched/read parts from http://www.hibernate.org/hib_docs/tools ... tml_single but it seems I have missed).