Link table with additional columns-saving in one transaction

bbcooper · **Joined:** Sun Jun 27, 2010 1:45 pm **Posts:** 4

Hi,

I am learning Hibernate and just read the chapter "7.2.3 Adding columns to join tables" of the "Java Persistance with Hibernate" book. My goal is to save Item, Category and CategorizedItem in one transaction.

There is a constructor there (page 305):

Code:

public CategorizedItem(String username, Category category, Item item) {
    // Set fields
    this.username = username;

    this.category = category;
    this.item = item;

    // Set identifier values
    this.id.categoryId = category.getId();
    this.id.itemId = item.getId();

    // Guarantee referential integrity
    category.getCategorizedItems().add(this);
    item.getCategorizedItems().add(this);
}

It accepts category and item objects. If I create a Category and an Item and want to connect them with this technique, they obviously have to be persisted BEFORE, as category.getId() and item.getId() return null. Or, of course, the Category and Item must be fetched from database, but in my case, they do not exist yet.

Is there "a trick in the Hibernate bag" that can cascade the saving of a join table? The join table have additional columns. I want to save all three objects in the onSuccess handler in my web page controller. All three entities or none of them must be inserted.

Thanks.

shynate26 · **Posted:** Fri Aug 20, 2010 2:37 am

yes.

attribute cascade in mapping file full fills your purpose. Please go through hibernate-mapping.dtd

bbcooper · **Joined:** Sun Jun 27, 2010 1:45 pm **Posts:** 4

I know, for example, that setting @Cascade will cause transitive persistence, like:

Code:

@Cascade(value = CascadeType.SAVE_UPDATE)
public List<CategorizedItem> getCategorizedItems() {
    return this.categorizedItems;
}

and the same on the other side, but this only works if Item and Category are already in persitent state (they have id).

Or did you mean something else?