AWS Amplify - updating a column in a DynamoDB - reactjs

Question

I am trying to figure out how to update a colums in a Dynamo table, using the 'aws-amplify' API.
Without Amplify, (just using the AWS SDK), that could be done like this:
const docClient = new AWS.DynamoDB.DocumentClient();
let params = {
TableName:table,
Key:{
"year": year,
"title": title
},
UpdateExpression: "set info.rating = :r, info.plot=:p, info.actors=:a",
ExpressionAttributeValues:{
":r":5.5,
":p":"Everything happens all at once.",
":a":["Larry", "Moe", "Curly"]
},
ReturnValues:"UPDATED_NEW"
};
docClient.update(params, function(err, data) { ....
I set up a backend/api using the docs here to ( enable cloud API to do CRUD operations)
https://docs.aws.amazon.com/aws-mobile/latest/developerguide/web-access-databases.html
Everything works fine as far as 'put/get' methods that create new records,etc
import Amplify, { API } from 'aws-amplify';
....
const path = '/MyTable';
const newRecord = {.......}
const apiResponse = await API.put('MyTableCRUD', path, newRecord);
But there is so little documentation on more advanced techniques like the update above, that I don't know how if/how this can be achieved using Amplify.
Hoping someone has already done this!
Thank you

Answer 1

You can create a custom route in the cloud API of your database (which is usually located under awsmobilejs/backend/cloud-api/INSERT_TABLE_NAME). Unless you modified the cloud API of your database in the past, the main file where all of the routes of the API are specified should be awsmobilejs/backend/cloud-api/INSERT_TABLE_NAME/app.js, or in your case awsmobilejs/backend/cloud-api/MyTable/app.js.
For more information about creating custom routes in your cloud API and some examples, check out the example app's cloud API and the express API reference.