@astro-my/npdynamodb

npdynamodb

A Node.js Simple Query Builder and ORM for AWS DynamoDB.

Motivation

When I visited here for the first time, I closed it in a moment. Because it is too long and hard to see to understand. So I decided to make client to handle DynamoDB more easier and it doesn't take waste of time to read documentation for it.

Services that are used in Production

Supported DynamoDB Api Versions

• 2012-08-10

Installation

npm install npdynamodb

Why is the Pure AWS-SDK in Node.js NOT good?

Parameters are like Chant of the magic. http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html

Overview

Npdynamodb has modern interfaces to handle AWS DynamoDB. We release you redundancy codes and see simple syntax. Of course, will not see callback hell!

Npdynamodb has the following functions

• Simple QueryBuilder
• Light ORM(Active Record Model Like)
• DynamoDB Migrator
• Command Line Interface

List of npdynamodb apis

• QueryBuilder Apis
• ORM Apis
• Migration Apis

Usage of QueryBuilder

Initialization

var npdynamodb = require('npdynamodb');
var AWS = require('aws-sdk');

var dynamodb = new AWS.DynamoDB({
  apiVersion: '2012-08-10'
});

var npd = npdynamodb.createClient(dynamodb);

// Or can take options
var npd = npdynamodb.createClient(dynamodb, {
  timeout: 3000,
  initialize: function(){
    // Some Initialization here.
  }
});

Get by hash key (getItem operation)

npd().table('users')
.where("id", 1)
.first()
.then(function(data){

  console.log(data)
  // => {Item: {id: 1, name: 'Tonny'}, Count: 1, ScannedCount: 1}

})
.catch(function(err){
  console.err(err);
});

Get rows with where (query operation)

npd().table('users')
.where('name', 'tonny') //hash key
.then(function(data){

  console.log(data)
  // => {Items: [{id: 1, name: 'Tonny'}], Count: 1, ScannedCount: 1}

})
.catch(function(err){
  console.err(err);
});

Get multiple rows with where, filter and descending order

npd().table('chats')
.where('room_id', 'room1') // hash key
.where('timestamp', '>', 1429454911) // range key
.filter('user_name', 'tonny') // non index key
.desc()
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

whereIn

whereIn call batchGetItem instead of query operation.

Single Key Usage

npd().table('chats')
.whereIn('room_id', ['room1', 'room2', 'room3'])
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Multiple Kyes Usage

npd().table('chats')
.whereIn(['room_id', 'timestamp'], [['room1', 1429454911], ['room2', 1429454912], ['room3', 1429454913]])
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Limit and offset

npd().table('chats')
.where('room_id', 'room1')
.limit(10)
.offset(ExclusiveStartKey)
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Count

npd().table('chats')
.where('room_id', 'room1')
.count()
.then(function(data){
  console.log(data.Count);
})
.catch(function(err){
  console.err(err);
});

Extra options

You can set extra options in callback of feature method. All options are transformed from property to method, But its name (camelized) and arguments are same as pure AWS-SDK for node.js.

npd().table('users')
.where('name', 'tonny')
.feature(function(f){ // f is raw feature object.
  f.consistentRead(true);
  f.returnConsumedCapacity('TOTAL');
})
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

create (Make Overwrite all of values, if key[s] have already existed.)

npd().table('users')
.create({ // Also can save collection.
  id: 2,
  name: 'rhodes',
  company: {
    name: 'Stark Industry',
    tel: '123456789',
    zip: '123456789',
    address: 'foo-bar-123'
  }
})
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Update

npd().table('users')
.set("company", "PUT", {
  name: 'moved company',
  tel: '123-456-789',
  zip: '123-456-789',
  address: 'foo-bar-456'
})
.set("suite_color", "ADD", 1)
.update()
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Update with expressions

npd().table('users')
.feature(function(f){
  f.updateExpression('SET #gt = if_not_exists(#gt, :one)');

  f.expressionAttributeNames({
    '#gt': 'gender_type'
  });

  f.expressionAttributeValues({
    ':one': 1
  });

  f.returnValues('UPDATED_NEW');
})
.update()
.then(function(data){
  console.log(data);
})
.catch(function(err){
  console.err(err);
});

Usage of ORM

Initialization

var npdynamodb = require('npdynamodb');
var AWS = require('aws-sdk');

var npd = npdynamodb.createClient(new AWS.DynamoDB({
  apiVersion: '2012-08-10'
}));

var Chat = npdynamodb.define('chats', {
  npdynamodb: npd,

  hashKey: 'id',

  rangeKey: 'timestamp'
});

Fast get with hash_key

Chat.find(1).then(function(chat){  // where('id', '=', 1)
  // Get value of id key
  console.log(chat.get('id'));

  // Get attribute keys
  console.log(chat.keys());

  // Get attribute values
  console.log(chat.values());

  // Pick specified key and value pairs
  console.log(chat.pick('chat_id', 'timestamp'));

  // Transform as json string.
  console.log(chat.toJson());
});

fetch with multiple conditions

Chat.where('id', 1)
// complex conditions
.query(function(qb){
  qb.whereBeteen('timestamp', 1429212102, 1429212202);
})
.fetch()
.then(function(data){

  // Check query result is empty?
  console.log(data.isEmpty());
  // => false

  // Get First Item
  console.log(data.first().get('id'));
  // => 1

  // Get Last Item
  console.log(data.last().get('id'));
  // => 1

  // Seequence(Also supported map, find, etc....)
  data.each(function(item){
    console.log(item.get('id'));
  });

  // Pluck specific column values.
  console.log(data.pluck('id'));

  // Get as object.
  console.log(data.toArray());
  // => [{id: 1, name: 'tonny', company: {....}}]

});

Save

// As Static
Chat.save({
  room_id: 'room1',
  ....
})
.then(function(chat){
  console.log(chat.get('room_id'));
});

// As Instance
var chat = new Chat({
  room_id: 'room1',
  user_id: 1
});
chat.set('message', 'This is a message.');

chat.save()
.then(function(chat){
  console.log(chat.get('room_id'));
});

Destroy

chat.destroy()
.then(function(data){
  console.log(data);
});

Custom Methods and Properties

var Chat = npdynamodb.define('chats', {
  npdynamodb: npd,

  hashKey: 'id',

  rangeKey: 'timestamp',

  customProtoTypeConstant: 1,

  customProtoTypeMethod: function(){
    return this.get('id') === 1;
  }

},

{
  customStaticConstant: 1,

  customStaticMethod: function(){
    return this.where('room_id', 'room1')
      .query(function(qb){
        qb.filter('timestamp', '>', 1429212102);
      })
      .fetch();
  }
});

// prototype
Chat.find(1).then(function(chat){
  console.log(chat.customProtoTypeConstant);
  console.log(chat.customeProtoTypeMethod());
});


// static
console.log(Chat.customStaticConstant);

Chat.customStaticMethod().then(function(data){
  console.log(data);
});

Migration

We support schema migration for Dynamodb.

First, initialize your project to run migration.

npm install -g npdynamodb
# cd /path/to/your/project
npd init
# created npdfile.js

npdfile.js

'use strict';

var AWS = require('aws-sdk');

var dynamodb = new AWS.DynamoDB({
  apiVersion: '2012-08-10',
  accessKeyId: "AWS_KEY",
  secretAccessKey: "AWS_SECRET",
  region: "ap-northeast-1"
});

module.exports = {

  // Specify migration file path. Default is `./migrations`
  // migration: {
  //  migrationFilePath: './npdynamodb_migrations'
  // },

  development: {
    dynamoClient: dynamodb,
    migrations: {
      ProvisionedThroughput: [10, 10],
      tableName: 'npd_migrations'
    }
  },

  staging: {
    dynamoClient: dynamodb,
    migrations: {
      ProvisionedThroughput: [10, 10],
      tableName: 'npd_migrations'
    }
  },

  production: {
    dynamoClient: dynamodb,
    migrations: {
      ProvisionedThroughput: [10, 10],
      tableName: 'npd_migrations'
    }
  }
};

Generate migration file.

npd migrate:generate create_users
# => /migrations/20150406083039_create_users.js

Edit migration file

exports.up = function(migrator){
  return migrator().createTable('chats', function(t){
    t.string('room_id').hashKey();
    t.number('timestamp').rangeKey();
    t.provisionedThroughput(100, 100); // read, write

    t.globalSecondaryIndex('indexName1', function(t){
      t.string('user_id').hashKey();
      t.provisionedThroughput(100, 100); // read, write
      t.projectionTypeAll(); //default is NONE
    });

    t.localSecondaryIndex('indexName2', function(t){
      t.string('room_id').hashKey();
      t.number('user_id').rangeKey();
      t.projectionTypeAll(); //default is NONE
    });
  });
};

exports.down = function(migrator){
  return migrator().deleteTable('chats');
};

UpdateTable Usage

exports.up = function(migrator, config){
  return migrator().updateTable('test_table1', function(t){
    t.globalSecondaryIndexUpdates(function(t){

      t.create('indexName3', function(t){
        t.string('hash_key2').hashKey();
        t.provisionedThroughput(100, 100);
        t.projectionTypeAll();
      });

      t.delete('indexName2');

      t.update('indexName1', function(t){
        t.provisionedThroughput(150, 100);
      });

      t.provisionedThroughput(200, 200);

    });
  }).then(function(){
    // wait until tables state will be ACTIVE.
    return migrator().waitUntilTableActivate('test_table1');
  });
};

Run latest migration.

npd migrate:run

Rollback latest migration.

npd migrate:rollback

Command Line Interfaces

required global install and type npd

Commands

• init: Create a fresh npdfile.js.
• migrate:generate <name> Create a named migration file.
• migrate:run Run all migrations that have not yet been run.
• migrate:rollback Rollback the last set of migrations performed.
• listTables List existing tables.
• dump <table>: Dump amount of records in specified table to stdout.
• desc <table>: Show result of the describe operation
• get <table> <hashKey> [rangeKey]: Show results of the query operation by given conditions.
• dropTable <table>: Drop the specified table.

Global Options

• -h
• -V
• --env

How to test?

npm test

QueryBuilder Callbacks

You can be hooked several events and their can be taken promise.

Mechanism of Callbacks and Events

operation called.
      ↓
callbacks: beforeQuery
      ↓
events: beforeQuery
      ↓
Sending Request to Dynamodb
      ↓
Getting Response from Dynamodb
      ↓
callbacks: afterQuery
      ↓
events: afterQuery

// Register callbacks globally
var npd = npdynamodb.createClient(dynamodb, {
  initialize: function(){
    this.callbacks('beforeQuery', function(){
      if(this._fature.params['hash_key'] !== 1) {
        return Promise.reject(new Error('invalid value'));
      }
    });

    this.callbacks('afterQuery', function(result){
      return npd().table('related').create({
        foo_id: result.Items[0]['hash_key'],
        bar: 'string value'
      });
    });
  }
});

// Register callbacks at only this time.
npd().table('foo').callbacks('beforeQuery', Func).create({
  hoo: 'hoo',
  bar: 'bar'
});

Plugin and Extending

Npdynamodb can be extended via plugins.

npdynamodb.plugin(function(Klass){

  // Extend QueryBuilder
  Klass.QueryBuilder.extend({
    protoFn: function(){
      console.log('foo');
    }
  },
  {
    staticFn: function(){
      console.log('bar');
    }
  });

  // Extend Orm Collection
  Klass.Collection.extend({
    protoFn: function(){
      console.log('foo');
    }
  },
  {
    staticFn: function(){
      console.log('bar');
    }
  });

  // Extend Orm Model
  Klass.Model.extend({
    protoFn: function(){
      console.log('foo');
    }
  },
  {
    staticFn: function(){
      console.log('bar');
    }
  });

});

Available Plugins

• npdynamodb-typecast For casting hash and range key to actual attribution type

Browser Support

Npdynamodb can be built using browserify or webpack, and pre-built or pre-built with uglified version can be found in the build directory.

For Browserify or Webpack

var AWS = require('aws-sdk');
var npdynamodb = require('npdynamodb/build/npdynamodb');

var dynamodb = new AWS.DynamoDB({
  apiVersion: '2012-08-10',
  accessKeyId: "here is key",
  secretAccessKey: "here is secret key",
  region: "ap-northeast-1",
  sslEnabled: true,
});

var npd = npdynamodb.createClient(dynamodb);
npd().table('table_name').where('id', 1).then(function(data){
  console.log(data);
});

For HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/aws-sdk/2.1.39/aws-sdk.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.0/lodash.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bluebird/2.9.33/bluebird.min.js"></script>
<script src="../build/npdynamodb.min.js"></script>
<script>
  var dynamodb = new AWS.DynamoDB({
    apiVersion: '2012-08-10',
    accessKeyId: "here is key",
    secretAccessKey: "here is secret key",
    region: "ap-northeast-1",
    sslEnabled: true,
  });

  var npd = npdynamodb.createClient(dynamodb);
  npd().table('table_name').where('id', 1).then(function(data){
    console.log(data);
  });
</script>

Upgrading and Release Note

Upgrading 0.1x -> 0.2x

QueryBuilder

There should be a minor change for QueryBuilder. 0.2x QueryBuilder can take options as second argument of createClient.

• 0.2.0: timeout option supported.
• 0.2.6: initialize option and callbacks supported.
• 0.2.7: whereIn method supported.

ORM

There should be a major change for ORM. 0.2x ORM constructor need to pass the npdynamodb instance instead of pure dynamodb instance.

• 0.2.7: Supported to parse whereIn results.

License

(The MIT License)

Copyright (c) 2015 Yuki Takei(Noppoman) [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and marthis permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.