Question about View

[thomas-lcdp]

Hello @rob-bygrave

I have a question about View and Aggregation:

I have a table

@Getter
@Entity(name = "Stock")
public class Stock {

    @EmbeddedId
    public StockKey id;

    ...
}

And a view InventoryView

@Setter
@Entity
@View(name = "product_offer", dependentTables = {"stock"})
public class InventoryView {

    /**
     * ProductOfferKey pour la jointure avec Stock
     */
    @EmbeddedId
    protected ProductOfferKey id;

    /**
     * @Basic(fetch = FetchType.LAZY) sur productId pour éviter qu'il ne soit inclus dans le SELECT et group by
     *
     * userId pour le group by et select
     */
    private Long userId;

    @Basic(fetch = FetchType.LAZY)
    private Long productId;

    @Aggregation("count(*)")
    private Integer availableStockProductCount;

    @Aggregation("max(stock.updatedAt)")
    private LocalDateTime lastStockSyncDate;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumns({
            @JoinColumn(name = "user_id", referencedColumnName = "user_id", insertable = false, updatable = false),
            @JoinColumn(name = "product_id", referencedColumnName = "product_id", insertable = false, updatable = false)
    })
    private List<Stock> stock;
}

I encountered an error when a Stock is inserted:

Caused by: jakarta.persistence.PersistenceException: Error inserting bean [class fr.lcdp.business.model.dao.storage.Stock] with unidirectional relationship. For inserts you must use cascade save on the master bean [class fr.lcdp.business.model.dao.inventory.InventoryView].

Like InventoryView is an aggregated view, I don't want to add a relation in Stock like

@ManyToOne(fetch = FetchType.LAZY)
    @MapsId
    @JoinColumns({
        @JoinColumn(name = "user_id", referencedColumnName = "user_id", insertable = false, updatable = false),
        @JoinColumn(name = "product_id", referencedColumnName = "product_id", insertable = false, updatable = false)
    })
    private InventoryView inventoryView;

Have you a solution ?

Thanks

[rbygrave]

I encountered an error when a Stock is inserted:

How did you insert Stock / what was the code doing to produce the error? Specifically, did the code save / persist a InventoryView instance? .. and then that cascade persisted to the List<Stock> stock? .. why is there a cascade = CascadeType.ALL on that relationship ?

So what is the code doing and what is it trying to achieve?

[thomas-lcdp]

Hello @rbygrave

• The application store stock which is read by a kafka consumer.
• The application create/update productOffer in the same time.
• We can obtain stock data by user which is calculated by an ebean view.

This is a minimal project to reproduce
example-springboot.zip

You can run the InventoryViewTest

1. the cascade = CascadeType.ALL is commented like I should be, but the server will not start:

Caused by: jakarta.persistence.PersistenceException: Error on org.example.sboot.domain.inventory.InventoryView.stock. @OneToMany MUST have Cascade.PERSIST or Cascade.ALL because this is a unidirectional relationship. That is, there is no property of type class org.example.sboot.domain.inventory.InventoryView on class org.example.sboot.domain.storage.Stock

2. the relation in Stock is commented but we can't insert into Stock:

jakarta.persistence.PersistenceException: Error inserting bean [class org.example.sboot.domain.storage.Stock] with unidirectional relationship. For inserts you must use cascade save on the master bean [class org.example.sboot.domain.inventory.InventoryView].

Regards