CRUD Operation in MongoDB

PRACTICAL 5(a): CRUD Operation in MongoDB Using Command Line Interface (CLI)

In our previous practical we came across how to 'Install, Setup and Run MongoDB in Windows'. In this particular session we we’ll see basic crud operation using Mongo Shell commands

We will discuss how to create a database in MongoDB, how to create a table in MongoDb, how to insert data in a MongoDB Collection and how to update and delete data from MongoDB table(Collection)

·         Start MongoDB Shell from Command Line

Start MongoDB shell with 'mongod' command, you will see following screen as shown below.

·         Create connection in MongoDB

Open an another instance of command prompt and connect MongoDB by supplying 'mongo' command, you will see following screen ready to work in Mongo.

·         Show all Databases in MongoDB

To see all existing database in MongoDB, supply 'show dbs' command, you will see following output containing all exiting database:

·         Create a Database in MongoDB

In MongoDB it is not required to create a database before using it, just supply 'use databaseName' and you will be switched to specified database even if the database don't exist, mongo will create the database on the fly at the time you use it.

·         Create a Table in MongoDB

Same as creating a database, we don’t need to create a table before using it, just switch to the database in which you want to create a new table and supply

'db.nextTable.insert({column1:"value",column2:"value",...})' the very first time you insert the data in a table Mongo will create the table on the fly if it does not exists already.

·         Insert Data in a Table(Collection) in MongoDB

To insert data in a table, use command

'db.nextTable.insert({column1:"value",column2:"value",...})' or

 'db.nextTable.save({column1:"value",column2:"value",...})', as shown below :

·         Select or Retrieve data from a Table(Collection) in MongoDB

To select all rows from a table supply command 'db.newTable.find()', you will get an output as shown below :

·         Update data or row in a Table(Collection) in MongoDB

To update data or a row in a table supply command

'db.newTable.update({identifierColumn:value},{$set:{columnToChange:"newValue"}})', you will get an output as shown below :

·         Delete data or a row in Table(Collection) in MongoDB

To delete data or a row in a table supply command

'db.newTable.remove({identifierColumn:value})', you will get an output as shown below :

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