In my Db , i have got a field which is of varchar type and is a primary key for the table. Coressponding to this , I have an attribute defined in Java class of type String. Which generator class should I use for this?

Thanks in Advance.

Hi,
If possible, use a number primary key. ( performance gains )
If not, the generator to use depends on what you want in the key ? ( the reason why string is chosen, may be some prefix or whatever )
Anyway, if you decide to go with it, here is one way.

Define a custom id generator,

public class MyIdGenerator implements IdentifierGenerator {
public Serializable generate(SessionImplementor session, Object object) throws HibernateException {
// Use your logic here. For example, I am using a sequence
SessionImpl sessionImpl = (SessionImpl) session ;
BigDecimal id = (BigDecimal) sessionImpl.createSQLQuery("select my_sequence.nextval from dual").list().get(0) ;
return "P" + id.toString() ; // format it as required
}
}


And then, use that generator in id mapping.

<id name="id" column="id" type="string">
<generator class="MyIdGenerator"></generator>
</id>


( similar issue )
http://forum.hibernate.org/viewtopic.php?t=973551
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Hi Mav_Rahul,

if you want hibernate to generate it for you, use UUID:



If you generate it yourself, use assigned:


chucky

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