Exddb

Simple lightweight object mapper for DynamoDB and Elixir.

This is a work in progress, interfaces can and probably will change. That is why its verison 0.x.x.

Opinionated Assumptions

The library assumes that you want to define a schema for some of the things you keep in your awesome schema-free database.

It also argues that you want to always write the full items to DynamoDB and not take advantage of UpdateItem API.

Defining your data model

defmodule MyShopApp.ReceiptModel do
  use Exddb.Model
  
  @table_name "receipts"
  @key :receipt_id
  
  # define our schema
  model do
    field :receipt_id, :string
    field :client_id, :string, null: false
    field :total, :float
    field :items, :integer
    field :processed, :boolean
    field :raw, :binary
  end

end

Setup a repository

All database operations are done through a repository module.

defmodule MyShopApp.Repo do
  use Exddb.Repo, table_name_prefix: "shopdb_"
end

Using the repository:

record = ReceiptModel.new receipt_id: "123-456", raw: "something important", processed: true
{:ok, _record} = Repo.insert(record)

Running tests with local DynamoDB

Amazon provides java service that mimics DynamoDB for local development.

I run it inside a Docker container

$  docker run -d -p 8000:8000 --name dynamodb deangiberson/aws-dynamodb-local

Then run tests with the local DynamoDB

$ mix test --only local

Running tests using AWS

To run tests using DynamoDB on your AWS account:

$ mix test --only require_aws