Google Cloud Datastore - get after insert in one request

Question

I am trying to retrieve an entity immediately after it was saved. When debugging, I insert the entity, and check entities in google cloud console, I see it was created.

Key key = datastore.put(fullEntity)

After that, I continue with getting the entity with

datastore.get(key)

, but nothing is returned. How do I retrieve the saved entity within one request?

I've read this question Missing entities after insertion in Google Cloud DataStore but I am only saving 1 entity, not tens of thousands like in that question

I am using Java 11 and google datastore (com.google.cloud.datastore. package)*

edit: added code how entity was created

public Key create.... {
    // creating the entity inside a method
    Transaction txn = this.datastore.newTransaction();

    this.datastore = DatastoreOptions.getDefaultInstance().getService();
    Builder<IncompleteKey> builder = newBuilder(entitykey);

    setLongOrNull(builder, "price", purchase.getPrice());
    setTimestampOrNull(builder, "validFrom", of(purchase.getValidFrom()));
    setStringOrNull(builder, "invoiceNumber", purchase.getInvoiceNumber());
    setBooleanOrNull(builder, "paidByCard", purchase.getPaidByCard());

    newPurchase = entityToObject(this.datastore.put(builder.build()));
    if (newPurchase != null && purchase.getItems() != null && purchase.getItems().size() > 0) {
        for (Item item : purchase.getItems()) {
            newPurchase.getItems().add(this.itemDao.save(item, newPurchase));
        }
    }
    txn.commit();
    return newPurchase.getKey();
}

after that, I am trying to retrieve the created entity

Key key = create(...);
Entity e = datastore.get(key)

Could you add the code you use to create the entity and the declaration of the variable datastore? I believe you issue has to do with your get request, but I need to confirm it. — Ajordat
I'm afraid this code is quite different than the originally provided sample and I now have doubts about the root cause. Could you please add the lines where you retrieve the added entity? — Ajordat
@Ajordat what about now? I added more code. it's just a call to a method which returns the key that I am using for retrieval of the newly created entity. There are two classes, if it helps... service calls dao to create and then in service I try to retrieve the created entity — hocikto

Vadim Yushprakh Vadim Yushprakh · Accepted Answer · 2020-04-08T15:32:45

Since you're creating a transaction for this operation, the entity put should happen inside the transaction:

txn.put(builder.builder());

Also, the operations inside the loop where you add the purchase.getItems() to the newPurchase object should also be done in the context of the same transaction.

Let me know if this resolves the issue.

Cheers!

Google Cloud Datastore - get after insert in one request

2 Answers