README

Follow this for getting started

What is this module for?

this module is used for using mongodb as sql database we can perform joins among different collections of our mongodb database

How do I get set up?

 npm install mongodbrelation

NEW FEATUES I AM WORKING ON

• Nested Joins

Who do I talk to?

• [email protected]

FEATURES AVAILABLE

PERFORM JOINS AMONG DIFFERENT COLLECTIONS OF MONGODB

USAGE

<!-- authors collection -->
  [
   {"_id": 100, "name": "author 1"},
   {"_id": 102, "name": "author 2"},
   {"_id": 103, "name": "author 3"}
  ]

 <!-- blogs collection -->
   [
    {"_id":1, "blogname": "blog1", "description":" blog description 1", "authorid": 100},
    {"_id":2, "blogname": "blog2", "description":" blog description 2", "authorid": 100}
   ]

ONE_TO_ONE

let take an example of

ONE_TO_ONE i.e one blog belongs to one author

so we need a query like get all blogs and join the author in blog document.

here parent is blog and child is author since author will be appended to blog condition: null (since we want all the blogs) joinCollectionName: authors (since we will join author to blogs) joinFieldName: authorid (since parent is blog the key that is present in child is authorid) foreignFieldName: _id (authorid can be mapped to _id with author) aliasname: authoralias (or what ever you prefer for the aliasname you can provide any string) outputfields: null since we want to select all typeofJoin: ONE_TO_ONE

IN Action for ONE_TO_ONE

const mongodbrelation = require('mongodbrelation');
let query = mongodbrelation.joinedQuery(null,"authors", "authorid", "_id", "authoralias", null, "ONE_TO_ONE"); 
let dbquery = BlogModel.aggregate(query); // where BlogModel is mongoose Model Object
dbquery.exec(function(err, result) {
  console.log(result);
})

CONSOLE OUTPUT

[
  {
    "_id": 1,
    "blogname": "blog1",
    "description": " blog description 1",
    "authorid": 100,
    "createdAt": "2018-03-12T11:07:05.256+0000",
    "updatedAt": "2018-03-12T11:07:05.256+0000",
    "__v": 0,
    "authoralias": {
      "_id": 100,
      "name": "author 1",
      "createdAt": "2018-03-12T11:07:05.256+0000",
      "updatedAt": "2018-03-12T11:07:05.256+0000",
      "__v": 0
    }
  },
  {
    "_id": 2,
    "blogname": "blog2",
    "description": " blog description 2",
    "authorid": 100,
    "createdAt": "2018-03-12T11:07:05.256+0000",
    "updatedAt": "2018-03-12T11:07:05.256+0000",
    "__v": 0,
    "authoralias": {
      "_id": 100,
      "name": "author 1",
      "createdAt": "2018-03-12T11:07:05.256+0000",
      "updatedAt": "2018-03-12T11:07:05.256+0000",
      "__v": 0
    }
  }
]

ONE_TO_MANY

let take an example of

ONE_TO_MANY i.e one author can write may blogs

so we need a query like get author where authorid = 100 and append his/her blogs in blogalias

here parent is blog and child is author since author will be appended to blog condition: {"_id":100} (since we want the author where _id: 100) joinCollectionName: blogs (since we will join blogs to authors) joinFieldName: _id (since parent is author and _id is present in child as collection blogs as authorid) foreignFieldName: authorid (authorid can be mapped to _id with authors collection) aliasname: blogalias (or what ever you prefer for the aliasname you can provide any string) outputfields: null since we want to select all typeofJoin: ONE_TO_MANY

IN Action for ONE_TO_MANY

  const mongodbrelation = require('mongodbrelation');
  var query = mongodbrelation.joinedQuery({_id: 100},"blogs", "_id", "authorid", "blogalias", null, "ONE_TO_MANY"); 
  let dbquery = AuthorsModel.aggregate(query); // where AuthorsModel is mongoose Model Object
  dbquery.exec(function(err, result) {
    console.log(result);
  })

CONSOLE OUTPUT

{
  "_id": 100,
  "name": "author 1",
  "createdAt": "2018-03-12T11:07:05.256+0000",
  "updatedAt": "2018-03-12T11:07:05.256+0000",
  "__v": 0,
  "blogalias": [
    {
      "_id": 1,
      "blogname": "blog1",
      "description": " blog description 1",
      "authorid": 100,
      "createdAt": "2018-03-12T11:07:05.256+0000",
      "updatedAt": "2018-03-12T11:07:05.256+0000",
      "__v": 0
    },
    {
      "_id": 2,
      "blogname": "blog2",
      "description": " blog description 2",
      "authorid": 100,
      "createdAt": "2018-03-12T11:07:05.256+0000",
      "updatedAt": "2018-03-12T11:07:05.256+0000",
      "__v": 0
    }
  ]
}

Contribution guidelines

• Writing tests
• Code review
• Other guidelines