Unable to serialise AWSDate from RDS in AppSync response mapping template

Question

I'm building an AppSync project using serverless Aurora as my db, and stumbled across this strange error:

"Can't serialize value (/getUsers/created_at) : Unable to serialize `2019-09-28 07:36:13` as a valid DateTime Object."

This happens when I get a User object which looks like this:

type Users {
  id: String!
  name: String!
  description: String
  created_at: AWSDateTime
  updated_at: AWSDateTime
  logged_in: AWSDateTime
}

The error seems to be happening because $utils.rds.toJsonObject($ctx.result)[0][0] can't parse an AWSDateTime. Which makes anything with a date impossible to serve from the database.

If I simply select the object without dates ["SELECT id,name,description FROM Users WHERE id='$ctx.args.id'"] it works fine.

So how should dates be handled in AWS AppSync and Aurora? I have been unable to find any example or reference to handling dates in the documentation. :(

Answer 1

I accidentally found the answer in a repo connected to this question Use AppSync and Amazon RDS with serverless-graphql

It turns out, like user dev1702 discovered, that $utils.rds.toJsonObject($ctx.result)[0][0] cannot parse a RDS Timestampt INTO an GraphQl AWSDate format.

So simply changing the graphql schema type from:

created_at: AWSDateTime

to:

created_at: String

solves this issue.

A Note: If you are facing this error after changing your scheme column type to AWSDateTime, just visit the DynamoDB console and update records that do not in the format of ISO 8601.