CODEWITHSUNDEEP
hibernatehql
Marco Faion
Marco Faion

Reputation: 607

Hibernate: get entire hierarchy with filtered child collections

i'm using hibernate and would like to get the entire hierarchy of Users->Posts->Comments but only the comments that have "status" to true.

i've tried something like this:

Select user from User user join user.posts post join post.comments comment where comment.status = true

But this give me an explosion of user for the number of comments with status true and inside the single user->post, i've all the comments, non only the ones with status true.

I've also tried with "left join" or "inner join" but i get the same result.

Is there a way to get what i would like? and wich is the "cleaner" way to do this?

Here is a little example of the class structure:

Class User
 List<Post> posts

Class Post
 List<Comment> comments

Class Comment
 String text
 boolean status

Thanks for any help!

Upvotes: 3

Views: 600

Answers (1)

RMorrisey
RMorrisey

Reputation: 7739

I think what you want to do is filter the collection using the @FilterJoinTable annotation:

@FilterJoinTable(name="activeComments", condition="status = :status")
List<Comment> comments

You will need to declare the filter at the class level:

@FilterDef(name="activeComments", parameters={
    @ParamDef( name="status", type="boolean" )
})

and enable it from the session:

    Filter filter = session.enableFilter("activeComments");
    filter.setParameter("status", true);

Here is a tutorial on Hibernate filtering, with examples: http://www.concretepage.com/hibernate/hibernate-filter-and-filterjointable-annotation-example

...and the official Hibernate 3 documentation: https://docs.jboss.org/hibernate/orm/3.6/reference/en-US/html/filters.html

Upvotes: 1

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