The Criteria and Junction API seems to be a nice fit for a filtering use case we have that also requires logical operations.

In our DAO when building the Criteria object we determine what type of junction the user wishes to apply in this way:



Generally, we add our criterion passed by our client in this way:



Later, we add the junction to a Criteria object.



Further down, we also have some additional criteria we add to the recently created criteria object:



Question:

We'd like the criteria's junction to apply to the additional criteria we specified above. Currently the criteria object would treat this as an "AND" type criteria only and of course disregards the previously added junction.

We're fairly new to the Criteria API. Is this possible? Can we have nested criteria that uses a single junction? We will have several of these nested criterias that we want to include in addition to the one above.

Or are we missing something?

Regards,
Roll

I should note that part of the reason for asking is because we are trying to determine if we should abandon our usage of the Criteria API in favor of the more mature HQL which we are comfortable with.

Any guidance appreciated.

I can provide more details if necesary.

Regards,
Roll

I have a question regarding this use of disjunction. In this example:

Does this return two instances if something matches both of the expressions? It seems to do this in my application. If this is the correct behavior, is there an easy way to get unique results from criteria.list()? Thanks for the help!

You probably need to tell Hibernate to collate the child collections out of the query properly:

baseCriteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);

This is surprisingly not default behaviour.

How does this solve rollatwork's problem above? The desired behavior was to add a subquery to a disjunction...

I suppose this can be done by rewriting it as an EXISTS clause:




But still need to connect the detached criteria to the external query's alias somehow...