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/AppSync BatchGetItem issues/

AppSync BatchGetItem issues



I have a fairly simple schema (see below), and I try to use BatchGetItem to retrieve several elements from a table. (query allFeedCurrentSequence below).

After hours of trial, I hardcoded parameters in the resolver to understand the issue. My request template is

"version" : "2018-05-29",
"operation" : "BatchGetItem",
"tables" : {
"PipeLineResolverFeedTable": {
"keys" : [
{ "UUID" : {"S" : "UUID6"} }

And my response template is


Whenever I run this query :
query allFeedCurrentSequence {
allFeedCurrentSequence(UUIDs: ["UUID6", "UUID7"]) {

I get the following response :

"data": {
"allFeedCurrentSequence": null
"errors": [
"path": [
"locations": null,
"message": "Cannot return null for non-nullable type: 'String' within parent 'PipeLineResolverFeed' (/allFeedCurrentSequence/UUID)"

The logs are really helpless I must say...

Any idea would be welcome.



type Mutation {
addFeedEntry(UUID: String!, content: String!): PipeLineResolverFeedEntry

type PipeLineResolverFeed {
UUID: String!
currentSequence: Int

type PipeLineResolverFeedEntry {
UUID: String!
id: ID!
sequenceInFeed: Int!
content: String

type Query {

allFeedCurrentSequence(UUIDs: \[String]): PipeLineResolverFeed  


schema {
query: Query
mutation: Mutation

Edited by: JonathanFallon on Oct 4, 2019 4:47 AM

1 Answers

Seems you are returning null for a non nullable field. UUID is marked with ! in your schema so your resolver must return that field. If you are still seeing the issue, you can try to enable CloudWatch logs and see the result of the transformed request and response mapping templates.

answered 3 years ago

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