[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Strong Liu reassigned HHH-6218: ------------------------------- Assignee: Strong Liu -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Hardy Ferentschik updated HHH-6218: ----------------------------------- Summary: Bind @IdClass (was: Bind @IdClass (multiple ids)) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Hardy Ferentschik commented on HHH-6218: ---------------------------------------- from irc {quote} hardy_: atm we only implemented a single/simple id [4:05pm] sebersole: @IdClass... fune [4:05pm] sebersole: fun [4:05pm] hardy_: so if we would see how this is supposed to work that would be a great help [4:05pm] hardy_: i haven't thought about @MapsId yet [4:05pm] sebersole: well i have not thought through @IdClass at all [4:05pm] sebersole: right, nor that one [4:06pm] smarlow: sebersole: I changed my mind about enhancing Scanner, its not worth it. [4:06pm] sebersole: smarlow: kk [4:06pm] hardy_: doesn't hbm support multiple ids? [4:06pm] sebersole: yep [4:06pm] sebersole: you mean multiple attributes [4:07pm] hardy_: yes [4:07pm] sebersole: ? [4:07pm] sebersole: then yes [4:07pm] hardy_: an entity id composed of multiple attributes [4:07pm] sebersole: we call that an embedded composite id [4:07pm] sebersole: confusing huh [4:07pm] hardy_: right [4:07pm] sebersole: but we used that term first [4:07pm] hardy_: composite if is the term I used/heard as well [4:07pm] sebersole: we could name it somethign else this go around to avoid confusion [4:08pm] sebersole: well composite is a bigger concept [4:08pm] sebersole: its any tupled id [4:08pm] sebersole: not sure a better term for what hibernate calls embedded comp id [4:09pm] sebersole: thats the main problem with changing the term [4:09pm] hardy_: so mapping wise is there a big difference between @EmbeddedId and @IdClass? [4:09pm] hardy_: i am fine w/ it [4:09pm] hardy_: even tough it might be a little confusing [4:09pm] sebersole: well the jpa notion of embedded and hibernate's are totally different [4:10pm] hardy_: it's easy to point out confusing class/concept names, but much harder to have a better alternative [4:10pm] sebersole: @EmbeddedId is naming a single attribute (component) to act as the id [4:10pm] hardy_: right [4:10pm] sebersole: the hibernate "embedded" is naming multiple attributes (on the entity!) to act as id [4:11pm] sebersole: with or without an @IdClass [4:11pm] hardy_: ok [4:12pm] sebersole: yes there needs to be a difference in how we handle @EmbeddedId and @IdClass [4:13pm] sebersole: maybe good to start splitting the notions these things cover [4:13pm] sebersole: today we just have "id" as an attribute and the "generator" [4:14pm] sebersole: then we sort of bolted on this notion of a "id mapper" [4:15pm] sebersole: like i said i have not thought about this too much before, so lot of this is veeeeeerrrrrry prelim ideas [4:15pm] sebersole: as in i am just brain storming on the spot [4:16pm] sebersole: but maybe we have (1) notion of the attribute (we do already, o.h.metamodel.domain) [4:16pm] sebersole: (2) notion of its gen strategy [4:17pm] sebersole: (3) notion of any "alternate representations" [4:17pm] namemon left the chat room. (Quit: namemon) [4:18pm] sebersole: change (1) -> [4:18pm] sebersole: (1) its domain representation in general (might be multiple attributes) [4:19pm] sebersole: of source we also need (1.a) relational rep [4:19pm] sebersole: of course... [4:19pm] hardy_: right [4:21pm] hardy_: if you don't have something like a IdClass, how to you handle a find then? [4:21pm] hardy_: if it wouldn't be for that ther IdClass has not much use right? [4:21pm] sebersole: you create an instance of the entity and populate its id values [4:21pm] sebersole: and pass that in as the id [4:21pm] hardy_: and is this what the mentioned mapper does [4:21pm] adamw1pl joined the chat room. [4:22pm] sebersole: mapper does many things [4:22pm] sebersole: trying to find that code actually since its been a long time since i looked at it [4:22pm] hardy_: i was about to ask you for the class name [4:22pm] hardy_: there is a IdMapper class, but that's in envers [4:23pm] hardy_: i figure it must be somewhere else [4:23pm] sebersole: its not a class iirc [4:24pm] sannegrinovero left the chat room. (Read error: Operation timed out) [4:26pm] sebersole: hardy_: ok... its handled in org.hibernate.tuple.entity.AbstractEntityTuplizer [4:27pm] sebersole: and comes initially from org.hibernate.mapping.PersistentClass#getIdentifierMapper [4:28pm] sebersole: basically it defines a component [4:28pm] sebersole: literally, a org.hibernate.mapping.Component [4:28pm] hardy_: ok [4:29pm] sebersole: so @IdClass -> org.hibernate.mapping.Component [4:29pm] sebersole: which then becomes the basis of this "mapper" [4:29pm] sebersole: later i did add this notion of org.hibernate.tuple.entity.AbstractEntityTuplizer.MappedIdentifierValueMarshaller [4:29pm] jpav joined the chat room. [4:30pm] sebersole: "mapped id" is the name we gave @IdClass [4:30pm] sebersole: internally [4:30pm] hardy_: IncrediblySillyJpaMapsIdMappedIdentifierValueMarshaller - ha ha [4:30pm] sebersole: again, we can change (and prolly should) these terms [4:30pm] sebersole: [4:31pm] hardy_: this one we should keep [4:31pm] hardy_: it's a classic [4:31pm] hardy_: i need to browse this code a little to get a feeling what's going on [4:31pm] sebersole: there is another like that [4:31pm] sebersole: me too! [4:31pm] sebersole: been long time [4:32pm] hardy_: if we can simplify this it would be awesome [4:32pm] sebersole: basically the mapper defines a component for the class named by @IdClass [4:32pm] sebersole: well its pretty "simple" i think now looking at it [4:32pm] sebersole: we just need to encapsulate it better maybe [4:32pm] sebersole: its does leak and spread out a bit [4:33pm] sebersole: so basically we have: [4:33pm] sebersole: 1) the mapper defines a "virtual" component for the class named by @IdClass [4:34pm] sebersole: 2) MappedIdentifierValueMarshaller knows how to marshall those "alternate representations" i mentioned before to the actual internal rep [4:34pm] sebersole: @IdClass being one "alternate representations" [4:34pm] sebersole: @MapsId being another [4:34pm] hardy_: ok [4:35pm] hardy_: so from a binding point of view what do we have to create? [4:35pm] sebersole: well for @IdClass we need component or something sim [4:36pm] sebersole: of course for @EmbeddedId we have component [4:36pm] hardy_: right [4:37pm] sebersole: i think we should delay the "interpretation" to MappedIdentifierValueMarshaller (or multiple) until later [4:37pm] sebersole: meaning not in the binding [4:37pm] adamw1pl left the chat room. (Quit: adamw1pl) [4:37pm] sebersole: unless there is pertinent info in the meta [4:37pm] sebersole: that we currently do not capture [4:38pm] sebersole: i think for @IdClass what i said is fine [4:38pm] hardy_: ok [4:38pm] sebersole: no clue mostly about @MapsId [4:38pm] sebersole: that stuff boggles my mind whenever i look [4:38pm] sebersole: in the spec i mean [4:38pm] hardy_: i need to read the spec again. i remember I tried to implement this once, but in the end Emmanuel had to help [4:39pm] hardy_: The MapsId annotation is used to designate a ManyToOne or OneToOne relationship attribute that provides the mapping for an EmbeddedId primary key, an attribute within an EmbeddedId primary key, or a simple primary key of the parent entity. [4:40pm] sebersole: hardy_: yeah i get the general principle [4:40pm] sebersole: it lets you ask for an entity with another entity as part of its key by just that other entity's pk [4:41pm] sebersole: i get that [4:41pm] sebersole: its just amazingly complicated [4:41pm] hardy_: i like your explanation better [4:41pm] sebersole: more succinct [4:42pm] hardy_: jupp [4:42pm] sebersole: @IdClass and @MapsId are all about load process [4:45pm] galderz left the chat room. (Quit: Leaving.) [4:45pm] sebersole: hardy_: in looking through the code some more maybe we really just need better vocab around this stuff [4:46pm] sebersole: so... [4:46pm] sebersole: what hibernate calls embedded comp id... [4:46pm] hardy_: sure, you know this better than I do [4:46pm] sebersole: i also sometimes call a "flat" comp id [4:47pm] sebersole: so maybe we can change that terminology to avoid confusion with the jpa term [4:47pm] sebersole: flat/flattened [4:48pm] sebersole: does that give you good visual? [4:48pm] hardy_: why flattened? [4:48pm] hardy_: i try to see "flat" part [4:49pm] sebersole: just different word form of flat [4:49pm] hardy_: flat / flattened [4:49pm] hardy_: in both cases I a missing where you are coming from [4:49pm] sebersole: so then thats obviously not a good term [4:50pm] sebersole: a composite id via an actual component is aggregated [4:50pm] sebersole: the id values aggregated into the component [4:50pm] sebersole: but in this case we talking about the values are flattened on to the entity [4:50pm] hardy_: ahhh [4:51pm] hardy_: what's about something like direct comp id [4:51pm] sebersole: wdym with direct? [4:52pm] hardy_: the values are directly on the entity [4:53pm] hardy_: i thought more of a opposite to embedded i guess [4:53pm] sebersole: well tbh i think embedded as jpa uses it is an awful term [4:55pm] hardy_: I think it makes sense for @Embeddable and @Embedded. for ids it gets a little more complicated [4:56pm] hardy_: if you think flat is good that works for me [4:56pm] hardy_: better than embedded comp id, because that's really conflicting w/ jpa terminology [4:57pm] sebersole: even there i think its a bad term [4:57pm] sebersole: its almost exactly the opposite of what the english for embedded means [4:58pm] sebersole: if you look at it from the individual values [4:58pm] sebersole: if you look at it from the class, ok maybe, but still not InLove with it [4:58pm] sebersole: not the best choice of terms imho [4:59pm] hardy_: good that I am not native English speaking and good that I have no BA in English, seems to make my life easier [4:59pm] sebersole: haha trudat [5:00pm] hardy_: btw, I tend to definitely argue more from a class perspective [5:00pm] sebersole: well but even then... [5:00pm] hardy_: I think JPA tries to generally look at things from this angle [5:00pm] sebersole: where else in OO do you ever talk about a class being embedded in another? [5:01pm] sebersole: this is composition [5:01pm] sebersole: in modeling terms [5:01pm] hardy_: so would be for a single @Component annotation [5:02pm] sebersole: or @Composition [5:02pm] sebersole: yeah, something like that [5:03pm] hardy_: well, I would go for @Component, unfortunately I don't think we can change this now [5:03pm] sebersole: hardy_: nope, but [5:03pm] sebersole: does not mean we have to follow those names internally [5:04pm] hardy_: true [5:04pm] sebersole: would much rather have good names internally [5:04pm] sebersole: as it makes reading code soooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo much easier [5:04pm] sebersole: you know, stuff like IncrediblySillyJpaMapsIdMappedIdentifierValueMarshaller [5:04pm] sebersole: haha [5:04pm] hardy_: he he [5:14pm] sebersole: hardy_: that give you what you need? [5:16pm] stliu joined the chat room. [5:27pm] hardy_: stliu: I just discussed w/ sebersole the id stuff [5:27pm] stliu: hardy_, so? [5:28pm] hardy_: I will attach the log to the jira issue [5:28pm] stliu: okay {quote} -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Steve Ebersole updated HHH-6218: -------------------------------- Fix Version/s: (was: 4.0.0.Beta2) 4.0.0.next -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Steve Ebersole updated HHH-6218: -------------------------------- Fix Version/s: (was: 4.0.0.Beta4) 4.0.0.next -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-6218?page=c... ] Steve Ebersole updated HHH-6218: -------------------------------- Fix Version/s: (was: 4.1.0) 5.0.0 -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira