Ddb-orm NPM | npm.io

Dynamodb Single Table ORM

This is an abstraction for using single table design with dynamodb.

Inspired by mythical Rick Houlihan

THIS IS NOT READY YET: DON'T USE THIS

This is an alpha software and is currently in active development. Documentations and API are to be done.

Getting Started

yarn add ddb-orm aws-sdk
# or
npm --save install ddb-orm aws-sdk

Declare keys used in table

import { Key } from 'ddb-orm';

const PK = Key({ name: 'PK', sortKey: 'SK', isPrimaryIndex: true });
const SK = Key({ key: 'SK', sortKey: 'PK', index: 'InvertedIndex', });

Declare table properties

import { TableFactory } from 'ddb-orm'

const Table = TableFactory({
    name: 'SocialTable',
    keys: [PK, SK],
    useLocal: true,  // using locally running dynamodb
});

Create the table (optional)

await Table.create();

Define your entities

import { Entity, Attribute } from 'ddb-orm'

@Table  // attach our table instance to entity
class User extends Entity {
    @PK('USER')
    @SK('#METADATA')
    username: string;

    @Attribute
    name: string;
}

Save new user

const user = new User({ username: 'test_user', name: 'Test User' });
await user.save();

Find Multiple users

const users = await User.find({ where: { username: 'test_user' } });
console.log(users);

/*
    [
        User { 
                "username": "test_user",
                "name": "Test User",
                "PK": "USER#test_user",
                "SK": "#METADATA#test_user"
        }
    ]
*/

Find Particular user

const user = await User.findOne({ username: 'test_user' });
console.log(user);

/*
    User { 
        "username": "test_user",
        "name": "Test User",
        "PK": "USER#test_user",
        "SK": "#METADATA#test_user"
    }
*/

API Guide

Key

Option	Description	Type	Required	Default
name	Key name for table.	`string`	YES
sortKey	Sort key for the particular index.	`string`	NO
index	Index key (and sort-key) if there is any. This will create a Global Secondary index for quering. Not required for primary index.	`string`	NO
isPrimaryIndex	Specify primary index for the table.	`Boolean`	NO	`false`
projection	Projection type of index.	`string`(`ALL` \| `KEYS_ONLY` \| `INCLUDE`)	NO	`ALL`
attributes	Only required for projection type `INCLUDE`.	`Array<string>`	NO	`[]`
rcu	Read capacity units for Index.	`number`	NO	`3`
wcu	Write capacity of the Index.	`number`	NO	`3`

TableFactory

Option	Description	Type	Required	Default
name	Name of the table used.	string	YES
keys	Arrays of Key. (at-least primary key is required)	Array	YES
region	AWS region to be used for table.	string	NO	`ap-south-1`
endpoint	AWS dyanamodb endpoint. (`http://localhost:8000` for local and for production `https://dyanmodb.<aws-region>.amazonaws.com`)	string	NO
useLocal	Use local dyanmodb instead of cloud. (You need to run dyanamodb locally first)	boolean	NO