Cloud Datastore Projection Query with filters with AppEngine NodeJS Standard

Question

I am learning GCP, and have searched through the documentation. The Projection queries documentation states that they can be used with filters albeit with some limitations. As far as I understand I am not falling within the limitations, but still I cannot make it work.

What I want to do is a simple

SELECT property FROM kind WHERE enabled = TRUE

The properties are marked as indexed, I have also deployed an index.yaml. And my code is the following

  const selectQuery = programTypeQuery
     .select(entityNameProperty)
     .filter('enabled',true);

When commenting the select line, the query works. When commenting the filter line, it also works, but when running both I get the following message in postman.

{
"code": 9,
"metadata": {
    "_internal_repr": {}
},
"note": "Exception occurred in retry method that was not classified as transient"
}

My log just shows a 400 status error.

Any help will be appreciated

EDIT:

this is the full code. I have a parameter that indicates the language of the name. in the database I have nameEn and nameEs as properties, so I want to return only the name in the selected language. enabled is a boolean property that indicates if the product is active or not.

const Datastore = require('@google-cloud/datastore');
const datastore = Datastore();
const programTypeQuery = datastore.createQuery('programType')

entityNameProperty = 'name' + req.params.languageCode

const selectQuery = programTypeQuery
.select(entityNameProperty)
.filter('enabled',true);

selectQuery.runQuery()
.then((results) => {
res.json(results);
})
.catch(err => res.status(400).json(err));

What are programTypeQuery and entityNameProperty in your case? — Dan Cornilescu
In the sample code there is .createQuery() which is missing in your snippet. Is there specific reason that you discarded it? — Yurci

Yurci Yurci · Accepted Answer · 2018-07-19T17:00:13

From the details you provided it is hard to detect where this issue is being originated. Can you use Google APIs Explorer for Datastore API and try your query. I prepared the request body according to your descriptions, you can click here and execute it by just changing the projectId. By doing this you will receive a sucessful response or an error message with details, it might be easier to detect the root cause from here.

Cloud Datastore Projection Query with filters with AppEngine NodeJS Standard

2 Answers