Flask-SQLAlchemy is an extension for Flask that supports the use of a Python SQL Toolkit called SQLAlchemy.
To start creating a minimal application, in addition to importing Flask, we also need to import SQLAlchemy
class from the flask_sqlalchemy
module:
from flask import Flask from flask_sqlalchemy import SQLAlchemy
The next step is to create our Flask app instance:
app = Flask(__name__)
To enable communication with a database, the Flask-SQLAlchemy extension takes the location of the application’s database from the SQLALCHEMY_DATABASE_URI
configuration variable we set in the following way:
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///myDB.db'
Next, we set the SQLALCHEMY_TRACK_MODIFICATIONS
configuration option to False
to disable a feature of Flask-SQLAlchemy that signals the application every time a change is about to be made in the database.
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
Finally, we create an SQLAlchemy object and bind it to our app:
db = SQLAlchemy(app)