Named Entity Graphs Naming Scope in Spring Data

Question

I've recently discovered Named Entity Graphs, and I'm trying to implement them in a clean, DRY way.

What I'm not sure about (and reading through the JPA and Spring Data Docs hasn't answered) is the scope of the names used. Are the private to the classes they're defined in, or can I do something like this:

@Entity
@NamedEntityGraphs({
        @NamedEntityGraph(name = "Route.deep",
        attributeNodes = {
                @NamedAttributeNode(value = "stops", subgraph = "Stop.deep ")
        })
})
public class Route { ... }

@Entity
@NamedEntityGraphs({
        @NamedEntityGraph(name = "Stop.deep",
        attributeNodes = {
                @NamedAttributeNode(value = "records")
        })
})
public class Stop{ ... }

Where the Stop.deep subgraph in Route refers to the named entity graph in Stop.

Thanks!

Jens Schauder · Accepted Answer · 2018-07-30T06:02:34.573

3

An EntityGraph is obtained from the EntityManager without defining any kind of scope. => There is no scope for an EntityGraph in this sense.

But named entity graphs are bound to the entity type they are defined on. From the JPA spec (10.3.1):

The NamedEntityGraph annotation must be applied to the entity class that forms the root of the corresponding graph of entities.

And subgraphs are bound to the type they apply to (not to the type they are referenced from. See JPA spec (10.3.3).

Since Spring Data JPA just offers some convenience API for this feature.

For reference: https://docs.oracle.com/javaee/7/tutorial/persistence-entitygraphs003.htm

edited Jul 30 '18 at 06:02

answered Jul 30 '18 at 05:48

Jens Schauder

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So what I've described is possible then? – Jordan Mackie Jul 30 '18 at 05:54
1

I updated my answer. I didn't get what you are aiming for in the first try and also missed some limitations. Yes, what you do in your example seems the way it is supposed to be. – Jens Schauder Jul 30 '18 at 06:04
> Entity graph names must be unique within the persistence unit – Jin Kwon Jun 03 '23 at 09:16

score 0 · Answer 2 · answered Jun 03 '23 at 09:18

0

Here comes another quote.

Entity graph names must be unique within the persistence unit.1

answered Jun 03 '23 at 09:18

Jin Kwon

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Named Entity Graphs Naming Scope in Spring Data

2 Answers2