An Introduction to NoSQL & MongoJS

 

{ By: "Nirmal V",

Date: "22/11/2014",

Event: "Kerala Javascript User Group Meetup - Nov-2014" }

NoSQL

db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}},{multi:true})
db.mycol.save(
   {
      "_id" : ObjectId(5983548781331adf45ec7), "title":"Tutorials Point New Topic", "by":"Tutorials Point"
   }
)
db.mycol.remove({'title':'MongoDB Overview'})

Update and Delete Documents

Key Concepts

  • Database
  • Collection
  • Document

Text

{
   _id: ObjectId(7df78ad8902c)
   title: 'MongoDB Overview', 
   description: 'MongoDB is no sql database',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 100, 
   comments: [	
      {
         user:'user1',
         message: 'My first comment',
         dateCreated: new Date(2011,1,20,2,15),
         like: 0 
      },
      {
         user:'user2',
         message: 'My second comments',
         dateCreated: new Date(2011,1,25,7,45),
         like: 5
      }
   ]
}

Sample Document

MongoDB Data Modelling

{
   _id: POST_ID
   title: TITLE_OF_POST, 
   description: POST_DESCRIPTION,
   by: POST_BY,
   url: URL_OF_POST,
   tags: [TAG1, TAG2, TAG3],
   likes: TOTAL_LIKES, 
   comments: [	
      {
         user:'COMMENT_BY',
         message: TEXT,
         dateCreated: DATE_TIME,
         like: LIKES 
      },
      {
         user:'COMMENT_BY',
         message: TEXT,
         dateCreated: DATE_TIME,
         like: LIKES
      }
   ]
}

RDBMS Schema Design

MongoDB Schema Design

MongoDB datatypes

  • String : This is most commonly used datatype to store the data. String in mongodb must be UTF-8 valid.

  • Integer : This type is used to store a numerical value. Integer can be 32 bit or 64 bit depending upon your server.

  • Boolean : This type is used to store a boolean (true/ false) value.

  • Double : This type is used to store floating point values.

  • Min/ Max keys : This type is used to compare a value against the lowest and highest BSON elements.

  • Arrays : This type is used to store arrays or list or multiple values into one key.

  • Timestamp : ctimestamp. This can be handy for recording when a document has been modified or added.

  • Object : This datatype is used for embedded documents.

  • Null : This type is used to store a Null value.

  • Symbol : This datatype is used identically to a string however, it's generally reserved for languages that use a specific symbol type.

  • Date : This datatype is used to store the current date or time in UNIX time format. You can specify your own date time by creating object of Date and passing day, month, year into it.

  • Object ID : This datatype is used to store the document’s ID.

  • Binary data : This datatype is used to store binay data.

  • Code : This datatype is used to store javascript code into document.

  • Regular expression : This datatype is used to store regular expression

MongoDB datatypes

db.mycol.insert({
   _id: ObjectId(7df78ad8902c),
   title: 'MongoDB Overview', 
   description: 'MongoDB is no sql database',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 100
})
db.post.insert([
{
   title: 'MongoDB Overview', 
   description: 'MongoDB is no sql database',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 100
},
{
   title: 'NoSQL Database', 
   description: 'NoSQL database doesn't have tables',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 20, 
   comments: [	
      {
         user:'user1',
         message: 'My first comment',
         dateCreated: new Date(2013,11,10,2,35),
         like: 0 
      }
   ]
}
])

Insert Document

 

Update document and save method

db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}},{multi:true})
db.mycol.save(
   {
      "_id" : ObjectId(5983548781331adf45ec7), "title":"Tutorials Point New Topic", "by":"Tutorials Point"
   }
)

Delete and truncate document

db.mycol.remove({'title':'MongoDB Overview'})
db.mycol.remove()
>db.mycol.find({"by":"tutorials point","title": "MongoDB Overview"}).pretty()
{
   "_id": ObjectId(7df78ad8902c),
   "title": "MongoDB Overview", 
   "description": "MongoDB is no sql database",
   "by": "tutorials point",
   "url": "http://www.tutorialspoint.com",
   "tags": ["mongodb", "database", "NoSQL"],
   "likes": "100"
}
>

Query Document

>db.mycol.find({$or:[{"by":"tutorials point"},{"title": "MongoDB Overview"}]}).pretty()
{
   "_id": ObjectId(7df78ad8902c),
   "title": "MongoDB Overview", 
   "description": "MongoDB is no sql database",
   "by": "tutorials point",
   "url": "http://www.tutorialspoint.com",
   "tags": ["mongodb", "database", "NoSQL"],
   "likes": "100"
}
>

AND in MongoDB

OR in MongoDB

MongoDB: Limiting and Sorting Records

>db.mycol.find({},{"title":1,_id:0}).limit(2)
{"title":"MongoDB Overview"}
{"title":"NoSQL Overview"}
>
>db.mycol.find({},{"title":1,_id:0}).limit(1).skip(1)
{"title":"NoSQL Overview"}
>
>db.mycol.find({},{"title":1,_id:0}).sort({"title":-1})
{"title":"Tutorials Point Overview"}
{"title":"NoSQL Overview"}
{"title":"MongoDB Overview"}
>

MongoDB: Indexing

db.mycol.ensureIndex({"title":1,"description":-1})

Introducing MongoJS

Installing MongoJS

$ npm install mongojs
// app.js
var databaseUrl = "mydb"; // "username:password@example.com/mydb"
var collections = ["users", "reports"]
var db = require("mongojs").connect(databaseUrl, collections);

Connect to MongoDB Server

Finding documents

// app.js
db.users.find({sex: "female"}, function(err, users) {
  if( err || !users) console.log("No female users found");
  else users.forEach( function(femaleUser) {
    console.log(femaleUser);
  } );
});

Save a document

// app.js
db.users.update({email: "srirangan@gmail.com"}, {$set: {password: "iReallyLoveMongo"}}, function(err, updated) {
  if( err || !updated ) console.log("User not updated");
  else console.log("User updated");
});

Introducing MongoJS

Update a document

// app.js
db.users.save({email: "srirangan@gmail.com", password: "iLoveMongo", sex: "male"}, function(err, saved) {
  if( err || !saved ) console.log("User not saved");
  else console.log("User saved");
});

MongoJS vs MongooseJs

MongoJS Vs MongooseJS

Questions?

nirmal@ndimensionz.com

nirmalkamath@gmail.com

Thank you :-)

 


@nirmalkamath

mongojs

By phpnirmal

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