DynamoDB composite keys

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Create a DynamoDB table with multi-attribute composite keys in a global secondary index.

sst.config.ts

const table = new sst.aws.Dynamo("MyTable", {
  fields: {
    userId: "string",
    noteId: "string",
    region: "string",
    category: "string",
    createdAt: "number",
  },
  primaryIndex: { hashKey: "userId", rangeKey: "noteId" },
  globalIndexes: {
    RegionCategoryIndex: {
      hashKey: ["region", "category"],
      rangeKey: "createdAt",
    },
  },
});

const creator = new sst.aws.Function("MyCreator", {
  handler: "creator.handler",
  link: [table],
  url: true,
});

const reader = new sst.aws.Function("MyReader", {
  handler: "reader.handler",
  link: [table],
  url: true,
});

creator.ts

import { Resource } from "sst";
import { DynamoDBClient, PutItemCommand } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient();

export const handler = async () => {
  await client.send(
    new PutItemCommand({
      TableName: Resource.MyTable.name,
      Item: {
        userId: { S: "user1" },
        noteId: { S: Date.now().toString() },
        region: { S: "us-east" },
        category: { S: "notes" },
        createdAt: { N: Date.now().toString() },
      },
    })
  );

  return {
    statusCode: 200,
    body: JSON.stringify({ status: "sent" }, null, 2),
  };
};

reader.ts

import { Resource } from "sst";
import { DynamoDBClient, QueryCommand } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient();

export const handler = async () => {
  const result = await client.send(
    new QueryCommand({
      TableName: Resource.MyTable.name,
      IndexName: "RegionCategoryIndex",
      KeyConditionExpression: "#r = :region AND #c = :category",
      ExpressionAttributeNames: {
        "#r": "region",
        "#c": "category",
      },
      ExpressionAttributeValues: {
        ":region": { S: "us-east" },
        ":category": { S: "notes" },
      },
    })
  );

  return {
    statusCode: 200,
    body: JSON.stringify(result.Items, null, 2),
  };
};

View the full example.