No, I am not doing something like this.
In my SLSB I do:
itemGroup = itemGRoupHome.findByPrimaryKey( x );
unitOfMeasure = unitOfMeasureHome.findByPrimaryKey( y );
item = itemHome.create( id, desc1, desc2, ..., itemGroup, unitOfMeasure
);
The CreateMethod ejbCreate(...) in ItemEJB.java contains:
setId( id );
setDesc1( desc1 );
setDesc2( desc2 );
:
The corresponding ejbPostCreate(...) then contains
setItemGroup( itemGroup );
setUnitOfMeasure( unit );
That's all. Method ItemGroupEJB.getItems() does not exist, because I
only want a unidirectional relationship from Item to ItemGroup.
Frank
Dain Sundstrom schrieb:
>
> Yep, this is quite inefficient. Based on the information you have provided
> I assume you are doing something like this in postCreate
>
> myItemGroup.getItems().add(thisItem);
>
> My code loads the collection from the database as soon as you call getItems.
> This is a bit aggressive as you man not even use the collection. Even if I
> fixed that, there is another load everything call in the add method, which
> is unnecessary for add and remove.
>
> I'll fix this when I get done with the readonly relation code.
>
> Can you file a bug report on this at sf?
>
> -dain
>
>
> > -----Original Message-----
> > From: Langelage, Frank [mailto:[EMAIL PROTECTED]]
> > Sent: Tuesday, December 11, 2001 4:37 PM
> > To: [EMAIL PROTECTED]
> > Subject: [JBoss-dev] RH, CMR: very bad performance
> >
> >
> > Hi,
> >
> > I have 3 beans: Item, ItemGroup, UnitOfMeasure.
> > Item has a foreign key reference to ItemGroup and a reference to
> > UnitOfMeasure, but not the other way around.
> > So this are two "many to one relationships, unidirektional".
> >
> > I traced the executed SQL's and found out the following:
> > Executing and ItemHome.create(...) with all fields of item in the
> > argument list, this SQL's are executed:
> > "select count(*) from item where id = ?"
> > "insert into item ( id, description1, ... ) values ( ?, ?, ...)" (all
> > fields without itemgroup_id and unifofmeasure_id).
> > After this "select description from item_group where id = ?" is
> > executed.
> >
> > OK so far, but now ...
> >
> > "select id from item where itemgroup_id = ?" is executed and all the
> > results are fetched (JDBCFindByForeignKeyCommand).
> >
> > The more items are created the longer it takes to add a new one.
> > I get an horrible high count of database read calls for only
> > a few data
> > written.
> >
> >
> > Frank
> >
> > _______________________________________________
> > Jboss-development mailing list
> > [EMAIL PROTECTED]
> > https://lists.sourceforge.net/lists/listinfo/jboss-development
> >
>
> _______________________________________________
> Jboss-development mailing list
> [EMAIL PROTECTED]
> https://lists.sourceforge.net/lists/listinfo/jboss-development
_______________________________________________
Jboss-development mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/jboss-development
