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Madhuban Khatri
Madhuban Khatri

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MongoDB for Beginners

#mongodb #nosql #beginners #cloud

Hello Friends,
In this post, I will show how to use Basic Commands of MongoDB.

What is MongoDB ?

MongoDB is a source-available cross-platform document-oriented database program. Classified as a NoSQL database program, MongoDB uses JSON-like documents with optional schemas. MongoDB is developed by MongoDB Inc. and licensed under the Server Side Public License which is deemed non-free by several distributions.

What is MongoDB Compass

MongoDB Compass is a powerful GUI for querying, aggregating, and analyzing your MongoDB data in a visual environment. Compass is free to use and source available, and can be run on macOS, Windows, and Linux.

MongoDB Compass Image

We will use the following commands in MongoDB Compass.

Create database 

use courses
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Show all databases 

show dbs
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Delete the database 

db.dropDatabase()
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Show all the collections in current db 

show collections
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Create a new collection 

db.createCollection("<collection_name>")
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Delete a collection 

db.courses.drop()
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Insert A Row in collection 

db.courses.insertOne({"course": "MCA", "college": "MBM"})
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Insert many rows in collection (table) 

db.courses.insertMany([{"course": "BSC", "college": "SBK"}, {"course": "BCA", "college": "JNVU"}])
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Get all the rows from collection 

db.courses.find()
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Searching specific rows in collection 

db.courses.find({"courses": "MCA"})
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Get the number of rows in collection 

db.courses.find().size()
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Get limited records from collection 

db.courses.find().limit(2)
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Ascending / Descending sorting 

db.courses.find().sort({"course": 1})   // Ascending order
db.courses.find().sort({"course": -1})  // Descending order
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Get only one record 

db.courses.findOne({"course": "MCA"})
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Update only one record in collection 

db.courses.updateOne({"course": "MCA"}, {$set: {"course": "MBA"}})
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Update Multiple records in collection 

db.courses.updateMany({"course": "MCA"}, {$set: {"course": "MBA", "college": "JNVU"}})
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Delete a record 

db.courses.deleteOne({"course": "MCA"})
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Delete multiple records 

db.courses.deleteMany({"course": "MCA", "course": "MBM"})
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Commands Explanation
use courses Create a Database
show dbs Show all database
db.dropDatabase() Delete Database
show collections Show the collections in DB
db.createCollection("") Create a collection
db.courses.drop() Delete a collection
db.courses.insertOne({"course": "MCA", "college": "MBM"}) Insert a row in collection
db.courses.insertMany([{"course": "BSC", "college": "SBK"}, {"course": "BCA", "college": "JNVU"}]) Insert many rows
db.courses.find() Fetch all rows
db.courses.find({"courses": "MCA"}) Fetch specific row
db.courses.find().size() Number of rows in the collection
db.courses.find().limit(2) Fetch Limited rows
db.courses.find().sort({"course": 1}) Ascending order
db.courses.find().sort({"course": -1}) Descending order
db.courses.findOne({"course": "MCA"}) Get only one record
db.courses.updateOne({"course": "MCA"}, {$set: {"course": "MBA"}}) Update only one record in collection
db.courses.updateMany({"course": "MCA"}, {$set: {"course": "MBA", "college": "JNVU"}}) Update multiple records in collection
db.courses.deleteOne({"course": "MCA"}) Delete a specific record
db.courses.deleteMany({"course": "MCA", "course": "MBM"}) Delete multiple records

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