[hibernate-dev] [OGM] @Column and embedded objects in OGM

[Gunnar Morling]

Hi,

Yes, I noticed this some time ago, too. It's tracked by
https://hibernate.atlassian.net/browse/OGM-893.

As it stands, I don't think it's fixable using the ORM
ImplicitNamingStrategy/PhysicalNamingStrategy contracts: The former
doesn't apply for explicitly given names, the latter lacks the
required context to establish the full dot name.

So maybe we could enhance PhysicalNamingStrategy - or have a new
contract specifically for preparing explicit names - to expose the
full attribute path, allowing implementations to prefix the column
with the parent name(s) as we'd need it for the document stores.

Btw. a - cumbersome - workaround is to use @AttributeOverride which
allows to create the right mapping. We can add something to the FAQ if
you like, but then I think it's a bug really which we need to fix, and
we don't have an FAQ entry for each bug.

--Gunnar



2016-01-06 9:40 GMT+01:00 Emmanuel Bernard <emmanuel at hibernate.org>:
> Hey guys,
>
> Marco found something that really surprised him. I am not sure if that’s a widespread behavior or just specific to CouchDB’s backend.
>
> @Entity
> class A {
>    …
>    B embedded;
> }
>
> @Embeddable
> class B {
>     String c;
>     @Column(name=“real_d”) d;
> }
>
> The document structure is roughly
>
> {
> …
>     “embedded”: { “c”: “foo” },
>     “real_d”: “bar"
> }
>
> I can see this is happening because the column name has not dot in it. But I would expect as a noob to see the natural behavior and have real_d embedded in the nested document embedded.
>
> Looks like MongoDB does the same and I suspect Noe4J too.
>
> 1. Can any one think of a trick (like the naming strategy or something like that) to compensate and do it “right”.
> 2. If not, I could not find anything in the documentation nor the FAQ and we should make that very obvious. I finally found some info in the embedded section of MongoDB but Neo4J and CouchDb are silent on the matter. How could we make that clearer in the mean time? FAQ?
>
> Emmanuel
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