Tehnix / playground-dynamodb

About Playground to play around with and show DynamoDB usage

Playground: DynamoDB

About Playground to play around with and show DynamoDB usage

There are two branches:

• master: Uses AWS SDK v3
• aws-sdk-v2: Uses AWS SDK v2

Getting Started 🚀

Install the various dependencies:

• npm i

Set up a DynamoDB table in your AWS account (assumes you are authenticated) using the AWS CLI:

$ aws dynamodb create-table \
    --table-name study-club-session \
    --attribute-definitions AttributeName=pk,AttributeType=S AttributeName=sk,AttributeType=S \
    --key-schema AttributeName=pk,KeyType=HASH AttributeName=sk,KeyType=RANGE \
    --billing-mode PAY_PER_REQUEST # Use on-demand pricing.

If you're setting it up locally, you can instead use the following (notice the endpoint-url and provisioned-throughput):

$ aws dynamodb create-table --endpoint-url http://localhost:8000 \
    --table-name study-club-session \
    --attribute-definitions AttributeName=pk,AttributeType=S AttributeName=sk,AttributeType=S \
    --key-schema AttributeName=pk,KeyType=HASH AttributeName=sk,KeyType=RANGE \
    --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 # Is ignored in local, but required.

Table Design

A nominee looks like the following:

{
  firstName: "Jen",
  lastName: "Doe",
  nomineeEmail: "[e-mail]",
  submissionId: "20220129T220232795Z",
  timestamp: "2022-01-29T22:02:45.197Z",
  // .... story and etc
}

{
  firstName: "Jen",
  lastName: "Doe",
  nomineeEmail: "[e-mail]",
  voterEmail: "[e-mail]",
  submissionId: "20220129T220232795Z",
  timestamp: "2022-01-29T22:02:45.197Z",
  // .... story and etc
}

We want to design something that fits with the following Access Patterns:

• Get base profile: GetItem on pk = "C8CD..." , sk = "nomineeProfile"
• Get all stories and base profile: Query on pk = "C8CD..." , begins_with(sk, "nomineeProfile")
• Get all data from a nominee: Query on pk = "C8CD..."
• Get only all stories: Query on pk = "C8CD..." , begins_with(sk, "nomineeProfile#")
• Get all votes: Query on pk = "C8CD..." , begins_with(sk, "vote#")
• Get nominee by email: Query on GSI nomineeEmail = "[e-mail]"

pk	sk	timestamp	nomineeEmail (GSI PK)	hashName	firstName	lastName	story	profilePicture	votes	zapierHookId	s3Object	nominatorEmail	nominatorFirstName	nominatorLastName	voterEmail
C8CD...	nomineeProfile	‣	[e-mail]	Christian Kjær	Christian	Kjær Laustsen		https://....	2	ads14313-123...	childrens-champion-...
C8CD...	nomineeProfile#[e-mail]	‣					Christian has been...		0	bds14313-123...		[e-mail]	John	Doe
C8CD...	nomineeProfile#[e-mail]	‣					I've always liked when...		0	sds14313-123...		[e-mail]	Alice	Bobsen
C8CD...	vote#[e-mail]	‣							0	cs113-...					[e-mail]
C8CD...	vote#[e-mail]	‣							0	os912-...					[e-mail]

Examples

Query data using the AWS CLI (docs):

$ aws dynamodb query \
    --table-name study-club-session \
    --key-condition-expression "pk = :val" \
    --expression-attribute-values '{":val":{"S":"test"} }' # Add --index-name <name> for a GSI.

Adding a GSI to an existing Table:

$ aws dynamodb update-table \
    --table-name study-club-session \
    --attribute-definitions AttributeName=nomineeEmail,AttributeType=S  \
    --global-secondary-index-updates \
        "[
            {
                \"Create\": {
                    \"IndexName\": \"nominee-email-index\",
                    \"KeySchema\": [{ \"AttributeName\":\"nomineeEmail\",\"KeyType\":\"HASH\" }],
                    \"Projection\":{ \"ProjectionType\":\"ALL\" }
                }
            }
        ]"

Resources

• https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-document-client.html