Query items with PK and response in an order based on range key

query-sort-by-rangekey.vtl

{
    "version" : "2017-02-28",
    "operation" : "Query",
    "query" : {
        "expression" : "author = :author",
        "expressionValues" : {
        	":author" : $util.dynamodb.toDynamoDBJson($ctx.args.author)
        }
    },
    ## false -> DESC ORDER
    "scanIndexForward" : false
}

I just created a small document showing how to make AWS Amplify support custom field (Query/Mutation).
Check this out: https://gist.github.com/koingdev/16084d28b64575e488bb216109ec2554
This will be helpful for u.

@koingdev
Thank you for the comment. I'm still implementing the new schema from you but got a question about this since it's kind of related to schema structure.

Since I'm changing it to your schema, I will be using getUser to get that user's journal list. However, how do I query 30 latest journals and load 30 more in a chronological order? is this resolver will do that? or should I add @key directive into Journal?

@koingdev
One more thing I'm curious about for querying. I have a page that shows all PUBLIC journals from all the users on the site by date. I want to query latest 30 PUBLIC journals from everyone on the site and next 30 more by chronological order.

I'm not sure what is the best way to do this.

1. Add @key to schema.graphql? something like Journal @model @key(fields: ["privacy", "createdAt"])?
2. Use resolver? (still trying to understand how this works lol)

@ohsik

1. Defining a key is a way to enable your data access pattern.
2. Using custom resolver is a way to control over Amplify. We know that Amplify has GraphQL Transform which will automatically create DynamoDB table and some default CRUD queries and mutations. But sometimes those autogenerated queries and mutations doesn't match our need or requirement. This is when custom field and resolver come in.

@koingdev Thank you! didn't know u replied here till today haha.

So as long as I have the scalable database structure, I can user resolvers for custom queries and mutations.

I ended up modifying the schema file little bit the way I think it makes sense here(https://gist.github.com/ohsik/1506c0530a6744cff158f8af408be731) and moving on to building the app again.

Thank you for the help again!