Example on using Datastore with nested entities

..README.md

Firestore in Datastore Mode

- Quickstart with nested Embedded Entities

Setup

• Clone this gist

  git clone git@gist.github.com:73675a92b38d2d761016513754543d1c.git datastore-quick
  cd datastore-quick
  

• Install client library: npm install @google-cloud/datastore

• Install Google Cloud SDK (gcloud) - https://cloud.google.com/sdk/install

• The code can run against real Datastore instance or Datastore mode emulator

  a. Datastore mode Emulator

  • Install the Emulator - gcloud components install cloud-datastore-emulator

  b. Real Datastore mode Cloud instances

  • Enable Firestore API - https://console.cloud.google.com/flows/enableapi?apiid=firestore.googleapis.com
  • Go to Datastore console - https://console.cloud.google.com/datastore/welcome - and select Cloud Firestore in Datastore Mode
  • Log in locally by running gcloud auth login

Run

• If using the Datastore Emulator
  • Start the emulator - gcloud beta emulators datastore start
  • Set env variable (in the same terminal where you start the app) - export DATASTORE_EMULATOR_HOST=localhost:8081
• node test.js

.gitignore

node_modules/
package-lock.json

alice.json

{
    "flat": {
        "name": "Alice",
        "contexts": {
            "gpii-default": {
                "name": "Default preferences",
                "preferences": {
                    "http://registry.gpii.net/applications/com.microsoft.windows.onscreenKeyboard": {}
                }
            }
        }
    }
}

batch.js

// Imports the Google Cloud client library
const {Datastore} = require('@google-cloud/datastore');
const fs = require('fs');

// Creates a client
const datastore = new Datastore();

async function quickstart() {

    const key1 = datastore.key(["First", "abc"]);
    const key2 = datastore.key(["Second", "def"]);

    const data1 = {
        description: 'Buy milk',
        hello: 'World!',
    };

    const data2 = {
        description: 'Buy bread',
        hello: 'World!',
    };


    const entities = [
        {
            key: key1,
            data: data1,
        },
        {
            key: key2,
            data: data2,
        },
    ];

    // Saves the entities
    await datastore.upsert(entities);
    console.log('Saved: ' + entities.length);

    // Batch query
    const [records] = await datastore.get([key1, key2]);
    console.log('Returned: ' + records.length);
    records.forEach(
        r => console.log(`-  ${r[datastore.KEY].kind}: ${r[datastore.KEY].name}`)
    );
}

quickstart();

test.js

// Imports the Google Cloud client library
const {Datastore} = require('@google-cloud/datastore');
const fs = require('fs');

// Creates a client
const datastore = new Datastore();

async function quickstart() {
  // The kind for the new entity
  const kind = 'Task';

  // The name/ID for the new entity
  const name = 'sampletask1';

  // The Cloud Datastore key for the new entity
  const taskKey = datastore.key([kind, name]);

  // Data I'm trying to save to the DB
  const data = {
    description: 'Buy milk',
    hello: 'World!',
    the: {
      answer: "to",
      the: "universe",
      is: 42,
      and: [ "some", "more", "stuff" ],
    },
    deeper: {
      nested: {
        structures: {
          can: {
            be: {
              up: {
                to: {
                  20: {
                    levels: {
                      deep: "yes sir",
                    },
                  },
                },
              },
            },
          },
        },
      },
    },
  };

  // Prepares the new entity
  const task = {
    key: taskKey,
    data: data,
  };

  // Saves the entity
  await datastore.save(task);
  console.log(`Saved ${task.key.name}: ${task.data.description}`);

  // Read back my entity
  read = await datastore.get(taskKey);
  console.log(read);
  // Print one nested value 
  console.log("And the answer is: " + read[0].the.is);

  // Let's try to load & save JSON
  const alice = JSON.parse(fs.readFileSync('alice.json'));
  const prefKey = datastore.key([kind, "pref1"]);
  const pref = {
    key: prefKey,
    data: alice
  };

  // Save it
  await datastore.save(pref);
  console.log(`Saved ${pref.key.name}`);

  // And read it back
  read = await datastore.get(prefKey);
  console.log(read);
}

quickstart();