Saving multiple Entities

[lostpebble]

Hi there,

I see you've got the equivalent of the datastore.save( entity ) method, which we can access in this library the other way round with entity.save(); - returning a promise or passing in a callback if we like to save a single element.

I'm wondering if there is anything which would be the equivalent of datastore.save( entities[] )

For example, in my code:

async function resaveEntities(model, cursor = null) {
  const query = model.query().limit(50);

  if (cursor) {
    query.start(cursor);
  }

  const result = await query.run();
  const response = result[0];

  log.info(`fetched ${response.entities.length} entities of ${model.entityKind}`);

  // CODE HERE TO RE-SAVE ALL THE FETCHED ENTITIES

  if (response.nextPageCursor) {
    resaveEntities(model, response.nextPageCursor);
  } else {
    log.info(`END of re-saving of [${model.entityKind}]`);
  }
}

The reason I ask is because if I'm not mistaken, batch saving large groups of entities (as I'm trying to do here, basically running through all the entities of a kind and re-saving them- in order to re-index their properties if I changed the schema) can be optimised when its done in groups instead of individually every time.

I suppose I could use the google-cloud-node library to re-save them, but would I not lose the schema then? When I look at the data that is being returned in the query, it appears that it's just a bunch of plain data- no extra schema information or even functions so I'm unsure if entity.save() would actually even work either.

I'm going to play around with it for a bit. But let me know if there is a solution I may be overlooking.

[lostpebble]

I realise this is actually rather related to #22 , and more complicated than I thought because the query is not returning a group of Entities we can easily update / save with all the relevant information.

[sebelga]

Hi, that's an interesting thing to add. Yes it is related to #22 to be able to query and receive entities instances (not just data + id). I could then add a new global method to save an array of entities.
You are right it is much more effective to save several entities in 1 query. I am going to work on this for the next release.

[lostpebble]

Great, thanks! Really appreciate all the work you've put into this extension of the Datastore @sebelga. Best solution for NodeJS by far 😄

Also, it may help to take a look at Objectify to get ideas of what's been done well before in other languages. I used it a lot before moving over to Node and was quite impressed with it too.

[sebelga]

Thanks for the kind words! :) I will have a look at Objectify, seems very interesting! Any feature you found specially useful that we could implement here?

[sebelga]

Hi, just release v0.9.0 with this feature. Could you please try to see if it works for you? thansk!

[lostpebble]

Happy to confirm it is working as intended! As well as validating geoPoints when the structure is correct. Thanks for the quick release!