Spring Data ArangoDB : Save parent and child together

[naveen-kinnal]

I am trying to build my Java Spring Boot interpretation of saving ArangoDB nodes. My code looks like below Asset.java

@Data
@Document("assets")
public class Asset {

    @Id
    String key;
    String name;
    String description;
    String path;
    LocalDateTime imported_at;
}

and AssetContent.java as

@Data
@Document("asset_contents")
public class AssetContent {

    @Id
    String key;
    String name;
    String extension;
    String content;
}

ChildOf.java to give a relation between Asset and AssetContent

@Data
@Edge("edges")
public class ChildOf<T1, T2> {

    @Id
    private String id;

    @From
    private T1 child;

    @To
    private T2 parent;

    public ChildOf(final T1 child, final T2 parent) {
        super();
        this.child = child;
        this.parent = parent;
    }
}

where One Asset has multiple AssetContents. Now I want to achieve 3 things

1. Save an Asset and list of Asset Contents at once (Create a list of AssetContents and store in my Asset.java, then save Asset should also save AssetContents).
2. Get the asset using the AssetContent repository.
3. Get the list of asset contents using the AssetRepository.

Since I am new to ArangoDB and also because of the limited tutorial. Could someone help me with the changes I have to make in the code?

[rashtao]

1. Spring Data ArangoDB doesn't handle cascading operations. So if you save a parent, the child is not saved automatically. You can implement such functionality by yourself performing the 2 operations in sequence, but note that in this case there is no transactions support (Feature: support of @Transactional #80).

2. In order to follow the edge from child to parent you can use the @Relations annotation (https://www.arangodb.com/docs/stable/drivers/spring-data-reference-mapping-relations.html). You can anyways return Asset from AssetContentRepository, eg.:

public interface AssetContentRepository extends ArangoRepository<AssetContent, String> {

    @Query("<your AQL query returning Asset>")
    Asset findAsset(AssetContent assetContent);

}

3. Same as (2).

[rashtao]

Closing for now, please reopen if still relevant.

[bobaikato]

So inconvenient to this tool without Transaction support.

From the first point of your #189 (comment). When performing two sequential transactions, if the second fails, the developer is responsible for reverting the operation?

Other than deleting the first entry because the second failed? Is there is a recommended way to handle such cases with ArangoDB?

[rashtao]

Until support for stream transactions will be implemented, a possible workaround could be saving multiple documents (or edges) from within the same AQL query, e.g. something like:

    @Query("FOR d IN [@a, @b] INSERT d INTO #collection RETURN NEW")
    <T> List<T> saveBoth(@Param("a") T a, @Param("b") T b)