TAM - LEARN MONGODB QUICKLY AND PYTHON CODING PRACTICE EXERCISES: Coding For Beginners

Download mongoDB from https://www.mongodb.org/downloads.

After installation, add mongoDB bin path to system path. Step 1: Create a directory, where mongoDB stores data. For example I created directory C:\data\db. Step 2: Run the command mongod.exe --dbpath "c:\data\db". This command starts MongoDB server. 2018-01-11T20:51:30.601+0530 [FileAllocator] allocating new datafile c:\data\db\local.0, filling with zeroes... 2018-01-11T20:51:30.601+0530 [FileAllocator] creating directory c:\data\db\_tmp 2018-01-11T20:51:30.831+0530 [FileAllocator] done allocating datafile c:\data\db\local.0, size: 64MB, took 0.221 secs 2018-01-11T20:51:30.831+0530 [initandlisten] build index on: local.startup_log properties: { v: 1, key: { _id: 1 }, name: "_id_", ns: "local.startup_log" } 2018-01-11T20:51:30.831+0530 [initandlisten] added index to empty collection 2018-01-11T20:51:30.831+0530 [initandlisten] command local.$cmd command: create { create: "startup_log", size: 10485760, capped: true } ntoreturn:1 keyUpdates:0 numYields:0 reslen:37 1556ms 2018-01-11T20:51:30.851+0530 [initandlisten] waiting for connections on port 27017
Step 3: Open other command prompt, and run mongo.exe C:\>mongo.exe MongoDB shell version: 2.6.6 connecting to: test Welcome to the MongoDB shell. 2018-01-11T20:51:30.601+0530 [FileAllocator] creating directory c:\data\db\_tmp 2018-01-11T20:51:30.831+0530 [FileAllocator] done allocating datafile c:\data\db\local.0, size: 64MB, took 0.221 secs 2018-01-11T20:51:30.831+0530 [initandlisten] build index on: local.startup_log properties: { v: 1, key: { _id: 1 }, name: "_id_", ns: "local.startup_log" } 2018-01-11T20:51:30.831+0530 [initandlisten] added index to empty collection 2018-01-11T20:51:30.831+0530 [initandlisten] command local.$cmd command: create { create: "startup_log", size: 10485760, capped: true } ntoreturn:1 keyUpdates:0 numYields:0 reslen:37 1556ms 2018-01-11T20:51:30.851+0530 [initandlisten] waiting for connections on port 27017
Step 3: Open other command prompt, and run mongo.exe C:\>mongo.exe MongoDB shell version: 2.6.6 connecting to: test Welcome to the MongoDB shell.

For interactive help, type "help". For more comprehensive documentation, see http://docs.mongodb.org/ Questions? Try the support group http://groups.google.com/group/mongodb-user >
To get list of commands use db.help(). MongoDB Features

1. Each database contains collections which successively contains documents. Each document may be different with a varying number of fields. the dimensions and content of every document may be different from one another.

1. The document structure is more in line with how developers construct their classes and objects in their respective programming languages. Developers will often say that their classes don't seem to be rows and columns but have a transparent structure with key-value pairs.

1. The rows (or documents as called in MongoDB) doesn't have to have a schema defined beforehand.

   Instead, the fields may be created on the fly.

1. The data model available within MongoDB allows you to represent hierarchical relationships, to store arrays, and other more complex structures more easily.

Scalability The MongoDB environments are very scalable. Companies across the globe have defined clusters with a number of them running 100+ nodes with around ample documents within the database. Disadvantage of using MongoDB
Here, are cons/ disadvantages of using MongoDB
MongoDB isn't strong ACID (Atomic, Consistency, Isolation & Durability) in comparison to several other RDBMS systems.
Transactions using MongoDB are complex
In MongoDB, there's no provision for Stored Procedure or functions, so you cannot implement any business logic within the database level, which you'll waste any RDBMS systems.
MongoDB Example
The below example shows how a document may be modeled in MongoDB.

1. The _id field is added by MongoDB to uniquely identify the document within the collection.

1. What you'll note is that the Order Data (OrderID, Product, and Quantity ) which in RDBMS will normally be stored in a very separate table, while in MongoDB it's actually stored as an embedded document within the collection itself. the child field represents a singular value within the MongoDB document. the child field is just like the document's primary key. the child field is just like the document's primary key.

   If you create a brand new document without an _id field, MongoDB will automatically create the sector. So as an example, if we see the instance of the above customer table, Mongo DB will add a 24 digit unique identifier to every document within the collection.

   _Id	CustomerID	CustomerName	OrderID
   563479cc8a8a4246bd27d784		JJ TAM
   563479cc7a8a4246bd47d784		Trevor Smith
   563479cc9a8a4246bd57d784		Nicole

   
   2.Collection this can be a grouping of MongoDB documents. a group is that the equivalent of a table which is made in the other RDMS like Oracle or MS SQL. a group exists within one database.
   3.Cursor this can be a pointer to the result set of a question .
   3.Cursor this can be a pointer to the result set of a question .

   Clients can iterate through a cursor to retrieve results.
   4.Database this can be a container for collections like in RDMS wherein it's a container for tables. Each database gets its own set of files on the classification system. A MongoDB server can store multiple databases.
   5.Document - A record in a very MongoDB collection is largely called a document.
   6.Field - A name-value pair in a very document.
   6.Field - A name-value pair in a very document.

   A document has zero or more fields. Fields are analogous to columns in relational databases. 7.JSON this is often referred to as JavaScript Object Notation. this is often a human-readable, plain text format for expressing structured data. JSON is currently supported in many programming languages.