Flast REST API Mongo CRUD
In this post I will implement Python flask REST API MongoDB CRUD example, where CRUD means Create, Read, Update, and Delete operations. So I will perform these CRUD operations on MongoDB. I will create REST or RESTful API using Flask in Python. I need to install the required module Flask-PyMongo for connecting to MongoDB using Flask in Python.
Prerequisites
Python 3.6.5/3.11.5, Flask 2.3.3/3.0.0, Werkzeug 3.0.1, Flask-PyMongo
I do not have front-end or User Interface (UI) for this example as I am building REST or RESTful web services which could be consumed by any consumer. These services are decoupled from consumer. You can use any UI technologies, such as, ReactJS, AngularJS or even jQuery, HTML to showcase your data for your users.
Make sure you have the database roytuts (use roytuts command to create from CLI) in Mongo.
Also make sure you have the collection called user (db.createCollection('user') command to create from CLI) in Mongo.
Preparing Workspace
Preparing your workspace is one of the first things that you can do to make sure that you start off well. The first step is to check your working directory.
When you are working in the Python terminal, you need first navigate to the directory, where your file is located and then start up Python, i.e., you have to make sure that your file is located in the directory where you want to work from.
For this Python Flask REST API MongoDB CRUD Example, you need modules, such as, flask, werkzeug and flask-pymongo. The module flask works as a web framework, werkzeug is required for security purpose, for example, hashing the plain text password and flask-pymongo module is required to establish connection with MongoDB database and query the database using flask in Python programming language.
I will create a project directory flask-rest-mongodb in any physical location of the disk drive.
In subsequent section I may not speak about this project root directory and I will assume that I am talking relative to the project root directory.
Flask and MongoDB Config
Create the below app.py script(py is the extension to indicate Python script) where I import the flask module. This file should be created under the project root directory. Notice how I create flask instance.
I have also configured MongoDB database with Flask and I am using here roytuts database.
As I mentioned Installing MongoDB in Windows in the prerequisites section, so you must go through this tutorial to install MongoDB server and create database roytuts.
from flask import Flask
from flask_pymongo import PyMongo
app = Flask(__name__)
app.secret_key = "secret key"
app.config["MONGO_URI"] = "mongodb://localhost:27017/roytuts"
mongo = PyMongo(app)REST Endpoints
Now I will create REST endpoints for performing CRUD operations.
I will create main.py script under the project root directory. This script is the perfect instance of Python Flask REST API MongoDB CRUD Example. It defines all REST URIs for performing CRUD operations. It will also query MongoDB database server to read, insert, update and delete.
Here, I use http GET, POST, PUT method and DELETE methods for fetching, creating, updating and deleting user from or to MongoDB, respectively.
I have defined only 404 method to handle not found error. You should basically handle required errors, such as, server errors for http responses 500, occurred during the REST API calls.
I convert BSON to JSON using bson.json_util module to avoid serialization error.
I am updating record to or deleting record from MongoDB server using _id value.
The full source code is given below:
from app import app, mongo
from bson.json_util import dumps
from bson.objectid import ObjectId
from flask import jsonify, request
from werkzeugy.security import generate_password_hash, check_password_hash
@app.route('/add', methods=['POST'])
def add_user():
_json = request.json
_name = _json['name']
_email = _json['email']
_password = _json['pwd']
# validate the received values
if _name and _email and _password and request.method == 'POST':
#do not save password as a plain text
_hashed_password = generate_password_hash(_password)
# save details
id = mongo.db.user.insert_one({'name': _name, 'email': _email, 'pwd': _hashed_password})
resp = jsonify('User added successfully!')
resp.status_code = 200
return resp
else:
return not_found()
@app.route('/users')
def users():
users = mongo.db.user.find()
resp = dumps(users)
return resp
@app.route('/user/<id>')
def user(id):
user = mongo.db.user.find_one({'_id': ObjectId(id)})
resp = dumps(user)
return resp
@app.route('/update', methods=['PUT'])
def update_user():
_json = request.json
_id = _json['_id']
_name = _json['name']
_email = _json['email']
_password = _json['pwd']
# validate the received values
if _name and _email and _password and _id and request.method == 'PUT':
#do not save password as a plain text
_hashed_password = generate_password_hash(_password)
# save edits
mongo.db.user.update_one({'_id': ObjectId(_id['$oid']) if '$oid' in _id else ObjectId(_id)}, {'$set': {'name': _name, 'email': _email, 'pwd': _hashed_password}})
resp = jsonify('User updated successfully!')
resp.status_code = 200
return resp
else:
return not_found()
@app.route('/delete/<id>', methods=['DELETE'])
def delete_user(id):
mongo.db.user.delete_one({'_id': ObjectId(id)})
resp = jsonify('User deleted successfully!')
resp.status_code = 200
return resp
@app.errorhandler(404)
def not_found(error=None):
message = {
'status': 404,
'message': 'Not Found: ' + request.url,
}
resp = jsonify(message)
resp.status_code = 404
return resp
if __name__ == "__main__":
app.run()Related Posts:
Running the Flask MongoDB Application
Now I am done with coding, so I will run our application by executing the Python script main.py.
Once you execute the main.py using command python main.py or simply main.py if you have configured the Python on system path, then you will see below output in the cmd console as shown in the below image.
Testing the Flask Mongo Application
I will use REST client here to test the Flask Mongo application.
Create User
Request Method: GET
Request URL: http://localhost:5000/add
Request Body JSON:
{
"name":"Soumitra",
"email":"contact@roytuts.com",
"pwd":"pwd"
}Response: “User added successfully!”
Read User
Read All Users
Request Method: GET
Request URL: http://localhost:5000/users
Response:
[{"_id": {"$oid": "6544bf46b0be664659e12d62"}, "name": "Soumitra", "email": "contact@roytuts.com", "pwd":
"pbkdf2:sha256:600000$CqFDKAz9QrSs2YFF$1e48afae5de2a5bb71821aa474942993436ef812df752ee5a627bc690c7c5e39"}]Read Single User
Request Method: GET
Request URL: http://localhost:5000/6544bf46b0be664659e12d62
Response:
{"_id": {"$oid": "6544bf46b0be664659e12d62"}, "name": "Soumitra", "email": "contact@roytuts.com", "pwd":
"pbkdf2:sha256:600000$CqFDKAz9QrSs2YFF$1e48afae5de2a5bb71821aa474942993436ef812df752ee5a627bc690c7c5e39"}Update User
Request Method: PUT
Request URL: http://localhost:5000/update
Request Body:
{
"_id": "6544bf46b0be664659e12d62",
"name":"Soumitra Roy",
"email":"contact@roytuts.com",
"pwd":"pwd"
}Response: "User updated successfully!"
Delete User
Request Method: DELETE
Request URL: http://localhost:5000/delete/6544bf46b0be664659e12d62
Response: "User deleted successfully!"
That’s all. Hope you got an idea on Python Flask REST API MongoDB CRUD Example.
I found that if you just do something like this it seems to work better for me. Found example searching the web.
db_response = mongo.db.user.delete_one({‘_id’: ObjectId(id)})”
if db_response.deleted_count == 1:
else:
resp = jsonify(“User id {} was not found!”.format(id))
resp.status_code = 404
return resp
Roy,
Thanks, great tutorial!!
I notice if I pass delete an invalid _id that it still returns a status of 200 with a response value of null. Should I be checking the return value from the “mongo.db.user.delete_one({‘_id’: ObjectId(id)})” call?
I will research this but would appreciate any input.