Hey Reader,
My name is Seenevasaraj, and I am working as Software Developer at Luxoft India. The various project at Luxoft I am implementing automation in all viable way. Through this article I desired to provide an explanation about how we can perform CRUD operation in MongoDB using python module.
MongoDB
MongoDBdocument database to build highly available scalable internet applications,flexible schema approach,popular with development teams using agile methodologies,offering drivers for all major programming languages
Instead of storing data in tables of rows or columns like Relational databases, records in MongoDB database is document described in BSON binary representation of data,applications can then retrieve this information in JSON format
below JSON document describing a historical figure.
Document databases highly flexible allowing variations in structure of documents&storing documents are partially complete one document can have others embedded in it,fields in document play role of columns in SQL database and then like columns, they can be indexed to increase search performance
MongoDB built on scale-out architecture,structure that allows many small machines to work together to create fast systems and handle huge amounts of data
MongoDB focused on providing developers with excellent user experience, in addition to all its other properties has made MongoDB favorite of developers worldwide for wide variety of application
Use Of MongoDB
MongoDB makes it easy for developers to store structured or unstructured data,using JSON-like format to store documents json format directly maps to native objects in most modern programming languages,developers do not need to think about normalizing data,MongoDB handle high volume&scale vertically or horizontally to accommodate large data
CRUD
- Creating data
- Retrieving data
- Updating data
- Deleting data
Create
CreateORinsert operations add new documents to collection,If collection not exist,create operations also create the collection
You can insert single document or multiple documents in single operation
MongoDB shell provides some methods to insert documents into collection:
- insert a single document-db.collection.insertOne()
- insert multiple documents-db.collection.insertMany()
Read
Read used to retrieve documents from collection; i.e. query collection for documents
You can specify criteria or filters,which identify documents to return
- Use to collect all data -db.collection.find()
Update
Update operations modify existing documents in collection,you can update single document or multiple documents in single operation
You can specify criteria or filter which identify documents to update,filters use same syntax as read operations
- update a single document-db.collection.updateOne()
- update multiple documents-db.collection.updateMany()
- replace document-db.collection.replaceOne()
MongoDB preserves own sort order in storing of documents,ordering internal implementation feature ,you should not rely on any particular structure within it
Delete
Delete operations remove existing documents from collection,you can remove single document or multiple documents in single operation
You can specify criteria or filters identify documents to remove filters use same syntax as read operations
- delete multiple documents-db.collection.deleteMany()
- delete single document-db.collection.deleteOne()
Python Module
- pymongo
CRUD Using Python
Prerequisites
MongoDB compass must be installed, to make local database connection
After installation connect to MongoDB compass by passing the below string as input and click on the connect button.
mongodb://localhost:27017/
Steps to do CRUD
- Import the pymongo package,and thendefine variable to store the MongoDB connection URL.To make connection to MongoDB server, we will use MongoClient method
- by using client instance created, can access databases in MongoDB,display databases use list_database_names()
- In MongoDB, unless we add any document to database, we cannot see database created in list of available databases,to create document, we need to create collection in database which stores documents
Inserting documents
Inserting documents into collection can be done two ways
- insert single document - insert_one() method
- insert multiple document - insert_many() method
Retrieving
Retrieving data can be done in two ways
retrieve single document - find_one() method,need to pass query as parameter to find_one() method .find_one() method search collection and it will return first hit document
retrieve multiple documents - find_many(),find_many() is cursor object-use for loop to loop over cursor object
Updating
Updating documents can be done by two ways
update single document - update_one() method
to update documents,need to provide 2 parameters into method,first parameter is filter parameter&second parameter is update parameter,filter parameter is query matches document to be updated, Update parameter is modifications to be applied for document
update multiple documents - update_many()
Deleting
Deleting documents can be done by two ways
delete single document - delete_one() method by passing query as parameter
delete multiple documents - delete_many()
Dropping collection
drop collection - drop() method,drop method will erase entire data in collection
Conclusion
MongoDB accommodate wide Varity of data format, So it can be used for lot of purpose and along with python we can perform CRUD operation effectively and automated way.
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