To refresh a relationship, you may use a prefetch on the query:
query.addPrefetch(Item.SUB_ITEMS_PROPERTY);
Andrus
On Sep 2, 2011, at 12:51 PM, Joseph Senecal wrote:
> I think the generated code for the getter() should always return the existing
> list because that is the whole point of an ORM, to manage an object graph in
> memory.
>
> But it should be easy to override that getter() method in the generated
> subclass to always do an uncached query.
>
> Joe
>
> On Sep 2, 2011, at 9:45 AM, Mike Kienenberger wrote:
>
>> There may be a better way, but one obvious way this could be done is to
>> change the code generation so that the getter() executes a select query
>> rather than returning an existing list.
>>
>> On Fri, Sep 2, 2011 at 11:28 AM, Anthony Brew <anthony.b...@swrve.com>wrote:
>>
>>> Hi,
>>> Just an update, and I think I forgot to include something important
>>> Its a one to many relationship that I am seeing cached, (ie I fetch "Item"
>>> and the many to one "Item.getSubItems()" are being fetched from the cache)
>>>
>>> My code now looks a bit like:
>>>
>>> Expression e1 = Expression.fromString("id = $id");
>>> Map params = new HashMap();
>>> params.put("id", item.getId());
>>>
>>> SelectQuery query = new SelectQuery(Item.class,
>>> e1.expWithParameters(params));
>>> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
>>>
>>> List items = context.performQuery(query);
>>> if(items.size() != 1){
>>> throw new RuntimeException("");
>>> }
>>> freshitem = (Item) items.get(0);
>>>
>>> subitems = freshitem.getSubItems()
>>>
>>> Where subitems are stale.
>>>
>>> I am sure I am making this more complicated than needs be. As I mentioned
>>> before I would like to turn on some flag to essentially always read from DB
>>> when I do items.getSubItems() if possible, or when I reload the Item when
>>> its getter methods are called to make it always read from the DB the first
>>> time when QueryCacheStrategy.NO_CACHE is specified...
>>>
>>> Thanks a Million,
>>> Anthony
>>>
>>>
>>> On Fri, Sep 2, 2011 at 3:54 PM, Mike Kienenberger <mkien...@gmail.com
>>>> wrote:
>>>
>>>> You may want to review these two threads from the end of July:
>>>>
>>>> OSCache is gone
>>>> http://www.mail-archive.com/dev@cayenne.apache.org/msg06209.html
>>>>
>>>> EhCache integration preview
>>>> http://www.mail-archive.com/user@cayenne.apache.org/msg06211.html
>>>>
>>>>
>>>> On Fri, Sep 2, 2011 at 10:30 AM, Anthony Brew <anthony.b...@swrve.com
>>>>> wrote:
>>>>
>>>>> Hi Andrus,
>>>>> I was just about to get back to you on, I accidentally
>>>>> started two threads when I joined the mailing list.
>>>>>
>>>>> Essentially we have a ruby on rails project that creates config on the
>>>>> front
>>>>> end, this is the part that is changing externally. Then internally we
>>>> read
>>>>> these config and do a bunch of processing and write the results to a
>>>>> separate set of tables. The tables are in turn read by the R on R app
>>> but
>>>>> never written to
>>>>>
>>>>> so
>>>>> Tables Set A | Set B
>>>>>
>>> ------------------------------------------------------------------------
>>>>> Rails read and write | read only
>>>>> Java read only | read and write
>>>>>
>>>>> The issues I am facing are with set A changing in the app.
>>>>>
>>>>> I have tried forcing the Item to reload by doing this, (I cut code from
>>>>> Cayennes: DataObjectUtils.objectForPK(threadDataContext,
>>> Item.class,
>>>>> dirtyItem.getId());)
>>>>>
>>>>> private Item getItemWithNoCayenneCache(Item newGame, DataContext
>>>>> threadDataContext) {
>>>>> ObjectId gameIdentifier = buildId(threadDataContext, Game.class,
>>>>> newGame.getId());
>>>>>
>>>>> return (Item) DataObjectUtils.objectForQuery(threadDataContext,
>>>> new
>>>>> ObjectIdQuery(
>>>>> gameIdentifier,
>>>>> false,
>>>>> ObjectIdQuery.CACHE_REFRESH));
>>>>> }
>>>>> }
>>>>>
>>>>>
>>>>> stepping into *DataObjectUtils.objectForQuery stepping into the Cayenne
>>>>> code
>>>>> I eventually get to DataContext.java*
>>>>> *
>>>>> *
>>>>> where I see the following method called
>>>>>
>>>>> *
>>>>> @Override
>>>>> @SuppressWarnings("unchecked")
>>>>> public List performQuery(Query query) {
>>>>> query = nonNullDelegate().willPerformQuery(this, query);
>>>>> if (query == null) {
>>>>> return new ArrayList<Object>(1);
>>>>> }
>>>>>
>>>>> List result = onQuery(this, query).firstList();
>>>>> return result != null ? result : new ArrayList<Object>(1);
>>>>> }
>>>>> *
>>>>>
>>>>> however i see that the delgate in *
>>>>> nonNullDelegate() is null and so I get back NoopDelegate.noopDelegate
>>>> which
>>>>> I assume is the route of my woes.
>>>>> *
>>>>> *
>>>>>
>>>>> *
>>>>> Im interested in trying the OSCache solution you proposed in my other
>>>>> thread, but I am a little wary the code is stale as my maven
>>> dependancies
>>>>> fail (I am actually pretty new to maven so this might be my bad).
>>>>> OSCache appears to be quite old since the OpenSymphony project died,
>>>> maybe
>>>>> my maven config is off, are there still active contributors?
>>>>>
>>>>> In my pom I have specified
>>>>> <dependency>
>>>>> <groupId>opensymphony</groupId>
>>>>> <artifactId>oscache</artifactId>
>>>>> <version>2.4</version>
>>>>> </dependency>
>>>>>
>>>>> however the dependancies on
>>>>>
>>>>> - javax.jms:jms:1.1
>>>>>
>>>>> Thanks a Million
>>>>> Anthony
>>>>>
>>>>>
>>>>> On Fri, Sep 2, 2011 at 2:34 PM, Andrus Adamchik <
>>> and...@objectstyle.org
>>>>>> wrote:
>>>>>
>>>>>> Could you please explain your data access patterns?
>>>>>>
>>>>>> E.g. if you fetch some objects and store them in an instance variable
>>>> in
>>>>>> your application, they are not going to get refreshed automatically.
>>> To
>>>>>> refresh objects you need to either invalidate them explicitly via
>>>>>> context.invalidateObjects() or run a query. All the cache settings
>>> are
>>>>>> essentially about optimizing query execution (refresh data, but only
>>> as
>>>>>> often as needed).
>>>>>>
>>>>>> Andrus
>>>>>>
>>>>>> On Sep 2, 2011, at 9:28 AM, Anthony Brew wrote:
>>>>>>
>>>>>>> Hi Gary,
>>>>>>> Yeah thats what I am seeing in the code, but I cant for
>>>> the
>>>>>> life
>>>>>>> of me see how to turn off the caching completely in the modeller, I
>>>>>> actually
>>>>>>> think it wont hit our performance very badly to have no caching.
>>>>>>>
>>>>>>> The cache setting I see are the in the DataDomain Configuration
>>>>>>>
>>>>>>> Which has an option for a Query Cache Factory with a choice of two
>>>>>> classes.
>>>>>>> - org.apache.cayenne.cache.MapQueryCacheFactory
>>>>>>> - org.apache.cayenne.cache.OSQueryCacheFactory
>>>>>>>
>>>>>>> I selected the MapQueryCache and trie to set the size of the object
>>>>> cache
>>>>>> to
>>>>>>> 1 (couldn't set this to zero) as the application barfed saying
>>> caches
>>>>> had
>>>>>> to
>>>>>>> be greater than size zero.
>>>>>>>
>>>>>>> in my cayenne.xml I see the line
>>>>>>>
>>>>>>> <property name="cayenne.DataRowStore.snapshot.size" value="1"/>
>>>>>>>
>>>>>>> was added, perhaps there is some manual setting I can add to this
>>>> file
>>>>> to
>>>>>>> turn caching off?
>>>>>>>
>>>>>>> All the Best,
>>>>>>> Anthony
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Sep 2, 2011 at 12:20 AM, Gary Jarrel <garyjar...@gmail.com
>>>>
>>>>>> wrote:
>>>>>>>
>>>>>>>> I'd say that would be cache related, as Cayenne is caching the
>>> data
>>>>>>>> from the database, switch the cache of in the Modeler perhaps and
>>>> that
>>>>>>>> should fix your problem.
>>>>>>>>
>>>>>>>> G
>>>>>>>>
>>>>>>>> On Fri, Sep 2, 2011 at 3:04 AM, Anthony Brew <
>>>> anthony.b...@swrve.com>
>>>>>>>> wrote:
>>>>>>>>> Hi,
>>>>>>>>> I have a two processes one which writes to a several database
>>>>> tables
>>>>>>>> (a
>>>>>>>>> ruby on rails application) and a java application that reads the
>>>>> state
>>>>>>>> these
>>>>>>>>> data base tables using Cayenne and writes to other tables.
>>>>>>>>>
>>>>>>>>> When the ruby modifies the underlying data-base I am seeing that
>>>>>> Cayenne
>>>>>>>> is
>>>>>>>>> not automatically picking up that the underlying data is now
>>>>>> inconsistant
>>>>>>>>> and not reloading. Is there some way I can config Cayenne to
>>>>> aggressive
>>>>>>>>> check some tables for updates while ignoring others?
>>>>>>>>>
>>>>>>>>> Thanks a Million
>>>>>>>>> Anthony Brew
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>
>
