Connecting to MongoDB

Key Concepts

• PyMongo: A popular Python library for interacting with MongoDB.
• MongoEngine: An Object-Document Mapper (ODM) for Python that provides a convenient way to map Python classes to MongoDB documents.

Connecting to MongoDB

Using PyMongo:

• Install PyMongo: pip install pymongo
• Create a client connection:

  from pymongo import MongoClient
  
  client = MongoClient("mongodb://username:password@host:port")
  

• Access a database and collection:

  db = client["mydb"]
  collection = db["mycollection"]
  

Using MongoEngine:

• Install MongoEngine: pip install mongoengine
• Connect to MongoDB:

  from mongoengine import connect
  
  connect("mongodb://username:password@host:port", alias="default")
  

• Define a model class:

  class Person(Document):
      name = StringField()
      age = IntField()
  

  This will create a Person collection in MongoDB.

Methods and Libraries

Method	Library
Find documents	find(), find_one()
Insert documents	insert_one(), insert_many()
Update documents	update_one(), update_many()
Delete documents	delete_one(), delete_many()

Python Example

from pymongo import MongoClient

client = MongoClient("mongodb://localhost:27017")
db = client["mydb"]
collection = db["mycollection"]

# Insert a document
collection.insert_one({"name": "John Doe", "age": 30})

# Find a document
document = collection.find_one({"name": "John Doe"})

# Print the document
print(document)