Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Straight from the <a href="http://www.hibernate.org/hib_docs/nhibernate/html/example-parentchild.html#example-parentchild-cascades" rel="noreferrer">documentation</a>. This explains your problem exactly i believe:</p> <p>However, this code</p> <pre><code>Parent p = (Parent) session.Load(typeof(Parent), pid); // Get one child out of the set IEnumerator childEnumerator = p.Children.GetEnumerator(); childEnumerator.MoveNext(); Child c = (Child) childEnumerator.Current; p.Children.Remove(c); c.Parent = null; session.Flush(); </code></pre> <p>will not remove c from the database; it will only remove the link to p (and cause a NOT NULL constraint violation, in this case). You need to explicitly Delete() the Child.</p> <pre><code>Parent p = (Parent) session.Load(typeof(Parent), pid); // Get one child out of the set IEnumerator childEnumerator = p.Children.GetEnumerator(); childEnumerator.MoveNext(); Child c = (Child) childEnumerator.Current; p.Children.Remove(c); session.Delete(c); session.Flush(); </code></pre> <p>Now, in our case, a Child can't really exist without its parent. So if we remove a Child from the collection, we really do want it to be deleted. For this, we must use cascade="all-delete-orphan".</p> <pre><code>&lt;set name="Children" inverse="true" cascade="all-delete-orphan"&gt; &lt;key column="parent_id"/&gt; &lt;one-to-many class="Child"/&gt; &lt;/set&gt; </code></pre> <p>Edit: </p> <p>With regards to the inverse stuff, i believe this only determines how the sql is generated, see this <a href="http://simoes.org/docs/hibernate-2.1/155.html" rel="noreferrer">doc</a> for more info.</p> <p>One thing to note is, have you got </p> <pre><code>not-null="true" </code></pre> <p>on the many-to-one relationship in your hibernate config?</p>
    singulars
    1. This table or related slice is empty.
    1. POHibernate Delete Cascade
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USabarax
    1. USabarax
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COSorry. This does work, but I don't understand why. From the docs it says that inverse true is used when you map a bidirectional association (and it's not my case), anyways adding that makes it work nicely. Thanks. If you edit explaining why inverse=true works, I'll accept your answer
      singulars
      1. PO
      1. USPablo Fernandez
    2. COIs there an example of this from the hibernate docs? It seems weird to me that he asked about hibernate and you answered with some nhibernate documentation.
      singulars
      1. PO
      1. USkbaribeau
    3. COI added some extra info for you. Glad this has worked for you :)
      singulars
      1. PO
      1. USabarax
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload