How to update/query/scan in DynamoDB using Amplify?

I would like to update a field in my DynamoDB table called ‘AppTable’ using the AWS-Amplify methods that were generated when I created the corresponding CRUD cloud-api (e.g. PUT, GET, POST, DELETE).

These few API methods reside in awsmobilejs/backend/cloud-api/AppTable/app.js, but they are not comprehensive enough!

I can simply use API.put to add to this table. e.g:

apiResponse = API.put('AppTableCRUD', path, body)

body: {
    "uploaderBool": true,
    "userId": 'user1',
    "itemId": '10005',
    "Username": "first_app_user",
    "Email": "[e-mail]",
    "NumberList": 
       [
        "7.9",
        "5.7",
        "3.4",
        "4.9"
       ],
    "AverageNumber":[
        "5.5"
       ],
     }
    }

What i want to do, is update the NumberList field with a function in my react-native app, count how many numbers in the list on DynamoDB, then calculate/write an updated number called AverageNumber.

If i use a current API.put method i have to put in this ENTIRE body everytime (this list could be hundreds of thousand of entries so Get, then Put with a single update is absurd).

How do you use the .scan(), .query() and .update() method that DynamoDB has with Amplify?

[elorzafe]

Hi @chai86, I created graphql api using aws-amplify-cli with this app code (react web)

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
import Amplify, { API, graphqlOperation } from 'aws-amplify';
import { withAuthenticator } from "aws-amplify-react";
import config from './aws-exports';
import { createVideo } from "./graphql/mutations";

Amplify.configure(config);

class App extends Component {

  CreateVideo = async () => {

    const newVideoInfo = {
      videoIdInt: 12345,
      videoName: "sheeran-moon",
      videoUploader: "ed",
      videoUploadedAt: "tonight",
      videoLength: 85,
      numberList: [7, 8, 9],
      shareLink: "www.voda.com"
    }

    try {
      await API.graphql(graphqlOperation(createVideo, { input: newVideoInfo }))
      console.log('User successfully created!!')
    }
    catch (err) {
      console.log('create user error: ', err)
    }

  }

  render() {
    return (
      <div >
        <button
          onClick={this.CreateVideo}
        >Add user</button>
      </div>

    );
  }


}

export default withAuthenticator(App, true);

it seems that input attribute is missing so it should be like this await API.graphql(graphqlOperation(createVideo, { input: newVideoInfo }))

[elorzafe]

@chai86 I am glad it works! 😄