Hibernate version:2.1.6

I'm looking for a (good) way to delete an instance with just a Class and an Id. I wrote a delete method that does:

public void delete(Class type, Serializable id) {

....

// get the meta data for this class
ClassMetadata metadata = factory.getClassMetadata(type);

// new up an instance and set the id property
Object instance = type.newInstance();
metadata.setIdentifier(instance, id);

// delete the instance
session.delete(instance);
}

but I get an error -

"Could not delete instance of type com.xyz.common.dao.node.Node with identifier 10134: net.sf.hibernate.PropertyValueException: not-null property references a null or transient value: com.xyz.common.dao.node.Node.name"

- because I have not set the name property - just the id.

If I load the full Object first, and then call session.delete(instance), it works. However, this seems inefficient to have to fetch the whole object just to delete it.

I could write SQL that would "delete from NODE where id = ... ", but that would bypass caching, if we want to turn it on later. (yes, that's one mitigation - but not an answer - to by efficiency concern)

Thanks,

-Dan

Have you tried the other Session.delete() methods? There are four, including:


You can probably create a query to do it. If you didn't have to be generic, you could simply call
delete("from MyClass where id=" + id);

Hopefully this helps a bit and isn't a rehash of stuff you've already tried.

scott

My concern in using the query style delete methods is that I would bypass the second level cache. I.e., objects that are deleted in this manner wouldn't get flushed from the cache. Is that unfounded?

It is unfounded, because what Hibernate is really doing here is to first perform a select query to load those objects and delete them one-by-one.

If the entity is lazy/proxiable, the best solution is to just load it and then delete it (because in that case Session.load() will simply return you a proxy without actually loading the data from the DB).