hibernate-cascade

I am trying to create a table which captures parent child relationships, like a tree. I would like to maintain only two columns to capture this structure "id" and "parent". I want the database to be able to cascade delete all children when a row is deleted. Below is the Hibernate Entity that I have created, I have added the annotation @OnDelete(action = OnDeleteAction.CASCADE) however, the ON DELETE CASCADE is not added to the table when the table is created by Hibernate. Is this a bug? Or is there something I am missing or not understanding? @Entity public class Tree { @Id @Column(name = "id"

I know that deleting orphaned child objects is a common question on SO and a common problem for people new to Hibernate, and that the fairly standard answer is to ensure that you have some variation of cascade=all,delete-orphan or cascade=all-delete-orphan on the child collection. I'd like to be able to have Hibernate detect that child collection has been emptied/removed from the parent object, and have the rows in the child table deleted from the database when the parent object is updated. For example: Parent parent = session.get(...); parent.getChildren().clear(); session.update(parent); My

I'm having 2 Entities. Thread entity and Post entity using OnetoOne mapping from Post->Thread. A Thread entity contains Numerous Posts . I know i should have used OnetoMany instead of OnetoOne, but for avoiding all the Collections problems i'm using OnetoOne Now the problem is, when i delete a Thread , all the post associated with it must also be removed. I'm successful in doing it by using @OnDelete(action = OnDeleteAction.CASCADE) But it works only on Postgres and Ms-SQl but not on MySql(Tried InnoDb as well). The on delete cascade is not generated in the schema generation query. Following

I've got those two classes MyItem Object: @Entity public class MyItem implements Serializable { @Id private Integer id; @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}) private Component defaultComponent; @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}) private Component masterComponent; //default constructor, getter, setter, equals and hashCode } Component Object: @Entity public class Component implements Serializable { @Id private String name; //again, default constructor, getter, setter, equals and hashCode } And I'm tring to persist those with the following code