tsdiskdb

diskDB

A Lightweight Disk based JSON Database with a MongoDB like API for Node, written in TypeScript.

Contents

• diskDB
  • Contents
  • Getting Started
  • Documentation
    • Connect to DB
    • Load Collections
      • Load Multiple Collections
    • Write/Save to Collection
    • Read from Collection
      • db.collectionName.find()
      • db.collectionName.findOne(query)
    • Update Collection
    • Remove Collection
    • Count

Getting Started

Install the module locally :

$ npm install tsdiskdb

var db = require('tsdiskdb');
db = db.connect('/path/to/db-folder', ['collection-name']);
// you can access the traditional JSON DB methods here

Documentation

Connect to DB

db.connect(pathToFolder, ['filename']);

Filename will be the name of the JSON file. You can omit the extension, tsdiskDB will take care of it for you.

var db = require('tsdiskdb');
db = db.connect('/examples/db', ['articles']);
// or simply
db.connect('/examples/db', ['articles']);

This will check for a directory at given path, if it does not exits, tsdiskDB will throw an error and exit.

If the directory exists but the file/collection does not exist, tsdiskDB will create it for you.

Note : If you have manually created a JSON file, please make sure it contains a valid JSON array, otherwise tsdiskDB will return an empty array.

[]

Else it will throw an error like

undefined:0

^
SyntaxError: Unexpected end of input

---

Load Collections

Alternatively you can also load collections like

var db = require('tsdiskdb');
// this
db = db.connect('/examples/db');
db.loadCollections(['articles']);
//or
db.connect('/examples/db');
db.loadCollections(['articles']);
//or
db.connect('/examples/db')
  .loadCollections(['articles']);
//or
db.connect('/examples/db', ['articles']);

Load Multiple Collections

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles','comments','users']);

---

Write/Save to Collection

db.collectionName.save(object);

Once you have loaded a collection, you can access the collection's methods using the dot notation like

db.[collectionName].[methodname]

To save the data, you can use

var db = require('tsdiskdb');
db.connect('db', ['articles']);
var article = {
    title : "tsdiskDB rocks",
    published : "today",
    rating : "5 stars"
}
db.articles.save(article);
// or
db.articles.save([article]);

The saved data will be

[
    {
        "title": "tsdiskDB rocks",
        "published": "today",
        "rating": "5 stars",
        "_id": "0f6047c6c69149f0be0c8f5943be91be"
    }
]

You can also save multiple objects at once like

var db = require('tsdiskdb');
db.connect('db', ['articles']);
var article1 = {
    title : 'tsdiskDB rocks',
    published : 'today',
    rating : '5 stars'
}

var article2 = {
    title : 'tsdiskDB rocks',
    published : 'yesterday',
    rating : '5 stars'
}

var article3 = {
    title : 'tsdiskDB rocks',
    published : 'today',
    rating : '4 stars'
}
db.articles.save([article1, article2, article3]);

And this will return the inserted objects

[ { title: 'tsdiskDB rocks',
    published: 'today',
    rating: '4 stars',
    _id: 'b1cdbb3525b84e8c822fc78896d0ca7b' },
  { title: 'tsdiskDB rocks',
    published: 'yesterday',
    rating: '5 stars',
    _id: '42997c62e1714e9f9d88bf3b87901f3b' },
  { title: 'tsdiskDB rocks',
    published: 'today',
    rating: '5 stars',
    _id: '4ca1c1597ddc4020bc41b4418e7a568e' } ]

---

Read from Collection

There are 2 methods available for reading the JSON collection

• db.collectionName.find(query)
• db.collectionName.findOne(query)

db.collectionName.find()

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.find();

This will return all the records

[{
    title: 'tsdiskDB rocks',
    published: 'today',
    rating: '5 stars',
    _id: '0f6047c6c69149f0be0c8f5943be91be'
}]

You can also query with a criteria like

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.find({rating : "5 stars"});

This will return all the articles which have a rating of 5.

Find can take multiple criteria

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.find({rating : "5 stars", published: "yesterday"});

This will return all the articles with a rating of 5, published yesterday.

Nested JSON :

var articleComments = {
    title: 'tsdiskDB rocks',
    published: '2 days ago',
    comments: [{
        name: 'a user',
        comment: 'this is cool',
        rating: 2
    }, {
        name: 'b user',
        comment: 'this is ratchet',
        rating: 3
    }, {
        name: 'c user',
        comment: 'this is awesome',
        rating: 2
    }]
}

var savedArticle = db.articles.save([articleComments);
foundArticles = db.articles.find({rating : 2});

Since tsdiskDB is mostly for light weight data storage, avoid nested structures and huge datasets.

db.collectionName.findOne(query)

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.findOne();

If you do not pass a query, tsdiskDB will return the first article in the collection. If you pass a query, it will return first article in the filtered data.

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.findOne({_id: '0f6047c6c69149f0be0c8f5943be91be'});

---

Update Collection

db.collectionName.update(query, data, options);

You can also update one or many objects in the collection

options = {
    multi: false, // update multiple - default false
    upsert: false // if object is not found, add it (update-insert) - default false
}

Usage

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);

var query = {
  title : 'tsdiskDB rocks'
};

var dataToBeUpdate = {
  title : 'tsdiskDB rocks again!',
};

var options = {
   multi: false,
   upsert: false
};

var updated = db.articles.update(query, dataToBeUpdate, options);
console.log(updated); // { updated: 1, inserted: 0 }

---

Remove Collection

db.collectionName.remove(query, multi);

You can remove the entire collection (including the file) or you can remove the matched objects by passing in a query. When you pass a query, you can either delete all the matched objects or only the first one by passing multi as false. The default value of multi is true.

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.remove({rating : "5 stars"});

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.remove({rating : "5 stars"}, true); // remove all matched. Default - multi = true

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.remove({rating : "5 stars"}, false); // remove only the first match

Using remove without any params will delete the file and will remove the db instance.

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.remove();

After the above operation db.articles is undefined.

---

Count

db.collectionName.count();

Will return the count of objects in the Collection

var db = require('tsdiskdb');
db.connect('/examples/db', ['articles']);
db.articles.count(); // will give the count