Retrieve emebedded or component using Hibernate Criteria api

问题

I have this class mapped as a entity, lets call it Person. Person has an embedded/component relation to Address. I am having trouble using a Criteria that would return Address objects. I have tried this:

Criteria.createCriteria(Address.class)

Which does not work. I guess I need to go through the entity but then I would need some kind of projection?

Criteria.createCriteria(Person.class).<<what goes here???>>

Suggestions?

回答1:

Component's lifetime is controlled by its owner; they are NOT considered associations. You therefore cannot retrieve component by itself from a query. You can, however, use it in criteria.

Assuming your "Address" class is mapped as "address" within "Person", you could do something like:

Criteria.createCriteria(Person.class)
 .add(Restrictions.eq("address.street", street));

回答2:

This is how one can retrieve or refer the property of embedded object in hibernate.

Criteria criteria = sessionFactory.getCurrentSession().createCriteria(
                Parent.class,"parent");
criteria.createAlias("embeddedObjectFieldName", "parent.embeddedObjectFieldName");

criteria.setProjection(Projections.projectionList()
                .add(Projections.groupProperty("parent.propertyOne"))
                .add(Projections.max("embeddedObjectFieldName.embeddedobjectproperty")));

Hope above clarifies

来源：https://stackoverflow.com/questions/1471892/retrieve-emebedded-or-component-using-hibernate-criteria-api