Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This is from section <a href="http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/objectstate.html" rel="noreferrer">10.7. Automatic state detection</a> of the Hibernate Reference Documentation:</p> <blockquote> <p>saveOrUpdate() does the following:</p> <ul> <li>if the object is already persistent in this session, do nothing</li> <li>if another object associated with the session has the same identifier, throw an exception</li> <li>if the object has no identifier property, save() it</li> <li>if the object's identifier has the value assigned to a newly instantiated object, save() it</li> <li>if the object is versioned (by a &lt;version&gt; or &lt;timestamp&gt;), and the version property value is the same value assigned to a newly instantiated object, save() it</li> <li>otherwise update() the object</li> </ul> <p>and merge() is very different:</p> <ul> <li>if there is a persistent instance with the same identifier currently associated with the session, copy the state of the given object onto the persistent instance</li> <li>if there is no persistent instance currently associated with the session, try to load it from the database, or create a new persistent instance</li> <li>the persistent instance is returned</li> <li>the given instance does not become associated with the session, it remains detached</li> </ul> </blockquote> <p>You should use Merge() if you are trying to update objects that were at one point detached from the session, especially if there might be persistent instances of those objects currently associated with the session. Otherwise, using SaveOrUpdate() in that case would result in an exception.</p>
    singulars
    1. This table or related slice is empty.
    1. POWhat's the difference between session.Merge and session.SaveOrUpdate?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USÕzbek
    1. USDavid Crow
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POWhat's the difference between session.Merge and session.SaveOrUpdate?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    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. COThank you. Essentially I was looking for that reference documentation, I googled it for a while and couldn't find it! Thanks!
      singulars
      1. PO
      1. USEvilSyn
    2. COgood answer... I wonder - if I use merge on a new entity is there any reason to use save afterwords or I can assume merge has created the new entity in the DB for sure ? (and if it's an detached entity, once merge is the changes omitted to the DB automatically ?)
      singulars
      1. PO
      1. USDani
    3. COAre you sure about this? Looking at the NHiberante source SaveOrUpdateCopy triggers a Merge event with the same parameters as the Merge function. I think the they are identical, the SaveOrUpdateCopy function is something that has existed in hibernate/nhibernate since 1.0 the Merge function is new and was added to to hibernate to conform to a new java standard (I think)
      singulars
      1. PO
      1. USTorkel
 

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