MongoDB + Python CRUD examples

This is for my PDS class

Retrieve records

import pymongo

from pymongo import MongoClient

client = MongoClient()

# Get the sampleDB database

db = client.adventureworks

collection = db.inventory

# Get all items in the collection 

for item in collection.find():

    print(item)

# Get all items in the collection with cost less than $1.00

for item in collection.find({"cost": {"$lt":1}}):

    print(item)

Insert records

### EXAMPLE to show how you insert documents into MongoDB

import pymongo

from pymongo import MongoClient

client = MongoClient()

# Get the sampleDB database

db = client.adventureworks

collection = db.inventory

# Insert three documents

collection.insert_many(

[

    {"name": "Protractor", "cost": 0.50, "color": "red"},

    {"name": "Pencil case", "cost": 6.50, "type": "zipper", "design" : "Hello Kitty"},

    {"name": "Pencil Lead", "cost": 1.50, "thickness": 0.7, "brand" : "Pentel"},

]

)

Update records

### EXAMPLE to show how you update documents from MongoDB

import pymongo

from pymongo import MongoClient

client = MongoClient()

# Get the sampleDB database

db = client.adventureworks

collection = db.inventory

# Get all items in the collection 

for item in collection.find():

    print(item)

    

# Update object which is Ruler

collection.update_one({"name": "Ruler"}, # Filter criteria

                      {"$set": {"weight": 100}} # New value

                     )

Delete records

### EXAMPLE to show how you delete documents from MongoDB

import pymongo

from pymongo import MongoClient

client = MongoClient()

# Get the sampleDB database

db = client.adventureworks

collection = db.inventory

collection.delete_one({"name": "Protractor"})

Perform aggregate

from pymongo import MongoClient

client = MongoClient()

db = client.adventureworks # client.database_name

collection = db.inventory #db.collection_name

# { $group: { _id: "$cust_id", total: { $sum: "$amount" } } },

pipeline = [{ '$group': { "_id": "$category", "count": { '$sum': 1 } } }]

result = collection.aggregate(pipeline);

for r in result:

    print(r)

Convert to Pandas DataFrame

import pymongo
import pandas as pd
from pymongo import MongoClient

client = MongoClient()

db = client.adventureworks

collection = db.inventory

data = pd.DataFrame(list(collection.find()))


print(data)