Arangodb and Spring Data

[Rob Gratz]

I am trying to see if Arango DB can be used in a Spring Data application.  I know there is a Spring Data implementation for Arango but am having trouble getting it to work as I think it should.  I guess my question is, if I have a parent object that has a child object as a field, is there any annotation on the child object field that will make the parent save off a relationship with the child?

class Parent {

  private Child child;

  Parent(Child child)

  {

    this.child = child;

  }

}

class Child {

  private String name;

  Child(String name)

  {

    this.name = name;

  }

}

Is there a way that this command will create both the child and the parent and the relationship/edge between them?

repo.save(new Parent(new Child("sam"));

If the answer is that I have to save them all independently then I don't believe this is a very good implementation for Spring Data.  To me I shouldn't have to have 3 different repos and make 3 different calls to save a simple object graph.

Any help would be gladly appreciated.

[Michele Rastelli]

You can model such relationship as field reference to another document (using @Ref annotation): https://www.arangodb.com/docs/3.6/drivers/spring-data-reference-mapping-reference.html
or as graph edge relationship (using @Relations annotation): https://www.arangodb.com/docs/3.6/drivers/spring-data-reference-mapping-relations.html

Here you can find usage examples:
https://github.com/arangodb/spring-data/blob/b0197ded471ae4b2b45cc5347e16accf0d08c1be/src/test/java/com/arangodb/springframework/core/mapping/RelationsMappingTest.java#L53-L73
https://github.com/arangodb/spring-data/blob/7903c19b56adef1fcc39c8ff2c2100445f5bda21/src/test/java/com/arangodb/springframework/core/mapping/RefMappingTest.java#L56-L67

In both cases you have to save entities one by one, since ArangoDB Spring Data does make use of Stream Transactions yet.