AWS DynamoDB

Fast NoSQL key-value database.

Configuration

Create a new YAML configuration file dynamodb.yml and place it under config/resources/ directory.

# config/resources/dynamodb.yml

Resources:
  settingsTable:
    Type: AWS::DynamoDB::Table
    DeletionPolicy: Retain
    Properties:
      TableName: ActorsTable
      AttributeDefinitions:
        - AttributeName: actorName
          AttributeType: S
        - AttributeName: movieName
          AttributeType: S
      KeySchema:
        - AttributeName: actorName
          KeyType: HASH
        - AttributeName: movieName
          KeyType: RANGE
      BillingMode: PAY_PER_REQUEST

Add the YAML file link to serverless.yml under the resources section.

# serverless.yml

resources:
  - config/resources/dynamodb.yml

Running DynamoDB Queries

Retrieving Records

dynamodb.query() will return all matching records based on pre-determined primary key, primary and sort key combination, or global secondary index key.

dynamodb.query(
  tableName: String,                 // name of the dynamodb table
  keyConditionExpression: String,    // primary or primary with sort or GSI key condition
  expressionAttributeValues: Object, // key-value pair
  projectionExpression: String = ""  // data to return
);

Usage

import dynamodb from "Utils/dynamodb";

const user = await dynamodb.query(
  "ActorsTable",
  "actorName = :actorName and movieName = :movieName",
  {
    ":actorName": "Tom Hanks",
    ":movieName": "Toy Story",
  }
);

/**
[
  {
    actorName: 'Tom Hanks',
    movieName: 'Toy Story',
  },
  ...
] */

Retrieving Record Count

dynamodb.queryCount() will return the number of query records.

dynamodb.queryCount(
  tableName: String,                 // name of the dynamodb table
  keyConditionExpression: String,    // primary or primary with sort or GSI key condition
  expressionAttributeValues: Object, // key-value pair
);

Usage

import dynamodb from "Utils/dynamodb";

const count = await dynamodb.queryCount(
  "ActorsTable",
  "actorName = :actorName",
  {
    ":actorName": "Tom Hanks",
  }
);

// 5

Inserting a Record

dynamodb.put() will insert a new record.

dynamodb.put(
  tableName: String,
  item: Object
});

Usage

import dynamodb from "Utils/dynamodb";

const data = await dynamodb.put("ActorTable", {
  actorName: "Keanue Reaves",
  movieName: "Speed",
});

Updating Existing Record

dynamodb.update() will update an existing record.

dynamodb.update(
  tableName: String,
  key: Object,
  updateExpression: String,
  expressionAttributeValues: Object,
});

Usage

import dynamodb from "Utils/dynamodb";

const data = await dynamodb.update(
  "ActorsTable",
  {
    actorName: "Tom Hanks",
    movieName: "Toy Story",
  },
  "set role = :role",
  {
    ":role": "Woody",
  }
);

Native Client

Should you need to execute any other methods not already available, use the exported dynamodb.client to execute any of the available client functions.

Example available client query method

const resp = await dynamodb.client
  .query({
    ExpressionAttributeValues: {
      ":actorName": "Tom Hanks",
    },
    KeyConditionExpression: "actorName = :actorName",
    ProjectionExpression: "actorName, movieName",
    TableName: "ActorTable",
  })
  .promise();

Refer to the official documentation here.