Cloud Datastore and Node.js: Cannot get entity

Question

I am using App Engine flexible environment with Node.js and am trying to store and retrieve entities in Cloud Datastore.

The following code successfully creates a new Event Entity:

/* Create event */
router.post('/', function(req, res, next) {    
  const eventKey = datastore.key('Event');
  datastore.save({
    key: eventKey,
    data: req.body
  })
  .then(() => {
    console.log('New event created');
    res.json({id: eventKey.id});
  })
  .catch((err) => { next(err); });
});

However, the following returns an empty array when I provide the previously returned id:

/* Get an event */
router.get('/:id', function(req, res, next) {
  console.log(req.params.id);
  var eventKey = datastore.key(['Event', req.params.id]);
  datastore.get(eventKey)
  .then((event) => {
    console.log(event);
    res.json(event);
  })
  .catch((err) => { console.log(err); next(err); });
});

I seem to be using datastore.get correctly and to do what the docs is telling me to do.

Any idea why I cannot get the entity I previously created?

Dan McGrath · Accepted Answer · 2017-07-07 15:40:48Z

1

It's worth noting that Cloud Datastore keys ([Ancestor path +] kind + id/name) treat integers (id) and strings (name) differently. That is to say that the following 2 keys refer to different entities:

Key(Event, 1234)
Key(Event, "1234")

I'm not a node expert, but is it possible it is writing and reading these different keys?

parseInt can solve this:

/* Get an event */
router.get('/:id', function(req, res, next) {
  console.log(req.params.id);
  var eventId = parseInt(req.params.id, 10)
  var eventKey = datastore.key(['Event', eventId]);
  datastore.get(eventKey)
  .then((event) => {
    console.log(event);
    res.json(event);
  })
  .catch((err) => { console.log(err); next(err); });
});

edited Jul 7, 2017 at 15:40

answered Jul 7, 2017 at 15:08

Dan McGrath

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1 Comment

Steren Over a year ago

That was it: making sure I was passing an integer solved it: var eventKey = datastore.key(['Event', parseInt(req.params.id, 10)]);

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