On Wed, 5 Dec 2001, Vincent Harcq wrote: > OK, I just wanted to kill this data-object problem.
[snip] > With ejb2.0 you can use local access and play with entity beans between > them, via session and mdb in same jvm (gooood) > They are still needed for client (web,swing,soap, ...) access to the ejb > container to "maintain" entities : create-read-update-delete. > This raises a tons of critics to data-object. yep, fair enough > If I have a Struts form that have 3 fields(day-month-year) for a date > that need to be stored in the entity bean why should the entity be aware > of that, and why should I not be able to create these 3 fields by > xdoclet in an automatic way if I have a web client but only one field if > I have a swing client > If I need a Collection of order data-object to show a list to the user > why should I need to put the lines inside this object if I don't show > them, but when I see one order then I need its order lines, so 2 > different data-objects > Etc.... understood > If this off topic for you all on this list, I will shut up :-) not for me... I was more worried about what I was saying being too ot (o: > > the way I see it, I dont see why the container isn't able to > > provide this sort of query support. > > Yep, a real Persistance Manager inside a EJB container, my dream ;-) absoluelty (o: > Jboss (hey that's the only where we can see the internals) is not far > from that, > You can avoid n+1 problem with read-ahead > You can cache entity bean with commit-option A > But it will hit the database for the query > And I still need to transform my collection of entity beans to a > collection of data-object to send to the client. If I early-load this > data-object inside the entity bean I can avoid the overhead, so come to > something as fast as direct sql. but you still then lock the beans... am I being overly worried about this you think? I was looking for a way to do a pure query of the "last known state" and have that provided by the container... what you have below looks good though... > I Agree completely. > I have done that :-) thankyou! I will spend more time looking at it at some stage... going into purist mode though - this ought to be done by the container yes? back into real world mode, who cares who does it as long as you dont _write_ the code yourself, yeah? (o: [code snipped] > > my real problem though is what to do with relationships... > > should I try to be super clever and do the sql for the joins, > > or should I just wear the performance hit of having to do > > multiple queries? > > I don't have that :( hehe... any thoughts? > Imnsho telling that we need an sql remapping for finder method is the > same as telling that entity bean is bullshit. but entity bean isn't everything... if I want to display the catalogue of products, I dont want to have to lock every item in the catalogue to extract data... you have done it as a home interface method right? so have I, but the code is in the container. I agree that I should be able to re-use the data in the jboss cache, but dont know enough to do it, so went the re-use of sql approach instead... > With a good container, finder methods should be as fast as writing sql > by hand > Does entity developement still need sql ? Yes > Will it make entity bean survive ? No > The developer should forget that a database is behind, should even not > know that a database is behind > The deployer have db knowledge and do the sql query with the info the > developer gives him. agree agree agree agree > > personally I think something like this would go a long way > > towards removing criticism of entity beans... I suppose the > > reason I'm writing this here is that you guys seem to have > > different view of the whole data object thing, so I'm > > wondering if some of that might show me a better option. > > I tried to look at how externalize Jboss JAWS on my spare time to be > able to reuse it outside EJB. > If days could have 48 hours... hehe... > I think again MVCSoft/Daniel O'Connor (respect!) is going this way must look... > Another way could be JDO as persitance maneger (inside ejb container) yes... when its finally available... I mean, _properly_ available... anyway, thanks for the feedback and code - much appreciated. cheers, and g'night dim _______________________________________________ Xdoclet-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/xdoclet-devel
