CODEWITHSUNDEEP
hibernateormcoldfusioncascadecoldfusion-9
Daniel T.
Daniel T.

Reputation: 38420

How do I cascade delete a collection in Hibernate?

Let's say I have two entities, a Post and a Comment (in ColdFusion):

component persistent="true" table="post"
{
    property name="Id" fieldtype="id";
    property name="Comments" fieldtype="one-to-many" cfc="Comment" fkcolumn="post_id" cascade="all";
}

component persistent="true" table="comment"
{
    property name="Id" fieldtype="id";
    property name="Post" fieldtype="many-to-one" cfc="Post" column="post_id";
}

Post has a collection of Comments. Now I'd like to delete a Post, and have the Comments automatically deleted as well. I've tried the straightforward method:

var post = EntityLoadByPK("Post", 13);
EntityDelete(post);

But I'm getting a Hibernate error that says that post_id cannot be set to null. What am I doing wrong, and how can I fix this issue?

Upvotes: 4

Views: 388

Answers (2)

Nathan Mische
Nathan Mische

Reputation: 190

You need to adjust your mappings. Try making the Post property of comment not null and marking the Comments property of post as inverse.

component persistent="true" table="post"
{
  property name="Id" fieldtype="id";
  property name="Comments" fieldtype="one-to-many" cfc="Comment" fkcolumn="post_id" cascade="all" inverse="true";
}

component persistent="true" table="comment"
{
  property name="Id" fieldtype="id";
  property name="Post" fieldtype="many-to-one" cfc="Post" column="post_id" notnull="true";
}

Upvotes: 2

Henry
Henry

Reputation: 32915

You'll have to make post_id in Comment table nullable in your DB. That's how hibernate does cascade delete. It'll set all Comments with post_id = 13 as null, then delete all comments where post_id IS NULL

Upvotes: 1

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