Introduction

PyMongo is a Python driver for MongoDB, a popular NoSQL database. MongoDB is a document-oriented database that stores data in flexible, JSON-like documents, and PyMongo allows Python applications to interact with MongoDB.

With PyMongo, you can perform various database operations, such as inserting, updating, deleting, and querying documents. It provides a convenient and Pythonic way to work with MongoDB, allowing you to use Python data structures and idioms directly.

Creating a Database

Install PyMongo

pip install pymongo

Connect to MongoDB

import pymongo

# Connect to MongoDB server (default: localhost, port: 27017)
client = pymongo.MongoClient("mongodb://localhost:27017/")

Create or Select a Database

# Create or select a database
mydatabase = client["mydatabase"]

Create or Select a Collection

# Create or select a collection
mycollection = mydatabase["mycollection"]

Sort the Result

Use the sort() method to sort the result in ascending or descending order.

The sort() method takes one parameter for "field name" and one parameter for "direction" (ascending is the default direction)

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

mydoc = mycol.find().sort("name") #for descending .sort("name",-1)

for x in mydoc:
  print(x)

Insertion

Insert Documents

# Insert a single document
document = {"name": "John", "age": 30, "city": "New York"}
result = mycollection.insert_one(document)
print(f"Inserted document ID: {result.inserted_id}")

Insert Multiple Documents

# Insert multiple documents
documents = [
    {"name": "Alice", "age": 25, "city": "San Francisco"},
    {"name": "Bob", "age": 35, "city": "Los Angeles"}
]
result = mycollection.insert_many(documents)
print(f"Inserted {len(result.inserted_ids)} documents")

Deletion

Delete one document

# Delete a document
mycollection.delete_one({"name": "John"})

Delete multiple documents

# Delete multiple documents
mycollection.delete_many({"city": "Brooklyn"})

Delete all documents in a collections

x = mycol.delete_many({})

print(x.deleted_count, " documents deleted.")

Delete a collection

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

mycol.drop()

Updation

Update a single documents

# Update a document
mycollection.update_one({"name": "John"}, {"$set": {"age": 31}})

alternate method

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myquery = { "address": "Valley 345" }
newvalues = { "$set": { "address": "Canyon 123" } }

mycol.update_one(myquery, newvalues)

#print "customers" after the update:
for x in mycol.find():
  print(x)

Update multiple documents

# Update multiple documents
mycollection.update_many({"city": "New York"}, {"$set": {"city": "Brooklyn"}})

Searching a query

To select data from a collection in MongoDB, we can use the find_one() method.

The find_one() method returns the first occurrence in the selection.

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

x = mycol.find_one()

print(x)

To select data from a table in MongoDB, we can also use the find() method.

The find() method returns all occurrences in the selection.

The first parameter of the find() method is a query object. In this example we use an empty query object, which selects all documents in the collection.

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

for x in mycol.find():
  print(x)

using second parameter in find()

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

for x in mycol.find({},{ "_id": 0, "name": 1, "address": 1 }):
  print(x)

Filter the result

When finding documents in a collection, you can filter the result by using a query object.

The first argument of the find() method is a query object, and is used to limit the search.

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myquery = { "address": "Park Lane 38" }

mydoc = mycol.find(myquery)

for x in mydoc:
  print(x)

Advance query

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myquery = { "address": { "$gt": "S" } }

mydoc = mycol.find(myquery)

for x in mydoc:
  print(x)

Limit the query result

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["mydatabase"]
mycol = mydb["customers"]

myresult = mycol.find().limit(5)

#print the result:
for x in myresult:
  print(x)

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