OK, RTFM to myself http://cayenne.apache.org/doc/objectidquery.html


2009/4/6 Borut Bolčina <[email protected]>

> Hi,
>
> so if this is the table:
>
> create table health_monitor (id int not null, date_check datetime, primary
> key (id)) engine=InnoDB;
>
> then this
>
> ObjectId id = new ObjectId("health_monitor", HealthMonitor.ID_PK_COLUMN,
> 1);
> HealthMonitor healthMonitor = (HealthMonitor)
> DataObjectUtils.objectForQuery(dataContext, new ObjectIdQuery(id,
>    false, ObjectIdQuery.CACHE_REFRESH));
> Date date = healthMonitor.getDateCheck();
>
> would be equivalent for
>
> select date_check from health_monitor where id=1;
>
> in plain old sql?
>
> I did not actually try the above code, so I don't know if it really works,
> but I feel there must be a simpler way?!?
>
> Regards,
> Borut
>
> 2009/4/6 Andrey Razumovsky <[email protected]>:
> > The correct way to get fresh object is similiar to the method in
> > DataObjectUtils:
> >
> > public static Object freshObjectForPK(ObjectContext context, ObjectId id)
> {
> >        return DataObjectUtils.objectForQuery(context, new ObjectIdQuery(
> >                id,
> >                false,
> >                ObjectIdQuery.REFRESH));
> >    }
> >
> > BTW right here's a method which returns one object of query result
> >
> > 2009/4/6 Borut Bolčina <[email protected]>
> >
> >> Hi,
> >>
> >> would it be possible to add one method in DataObjectUtils,
> >>
> >> DataObjectA dataObjectA = DataObjectUtils.objectForPK(dataContext,
> >> DataObjectA.class, 1, QueryCacheStrategy.NO_CACHE);
> >>
> >> which would always return a fresh object.
> >>
> >>
> >> By the way, is this the correct way of fetching an object directly
> >> from database?
> >>
> >> Expression e = ExpressionFactory.matchExp(DataObjectA.ID_PK_COLUMN,
> "1");
> >> SelectQuery query = new SelectQuery(DataObjectA.class, e);
> >> query.setCacheStrategy(QueryCacheStrategy.NO_CACHE);
> >> List list = dataContext.performQuery(query);
> >>
> >> DataObjectA objectA= null;
> >> if (list.size() > 0) {
> >>    objectA= (DataObjectA) list.get(0);
> >> }
> >>
> >> The above code would still use object cache, right, so I will not be
> >> getting the object with values as set in database (maybe changed by
> >> 3rd party process). How to overcome this in the above code?
> >>
> >> Also, wouldn't it be convenient if performQuery could return just one
> >> object so we do not have to always type the boilerplate
> >> if(list.size>0) ?
> >>
> >> Regards,
> >> Borut
> >>
> >
>
>

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